The partial differential equation (PDE) that cannot be solved exactly using the separation of variables method is 8²u/a² = ∂rª/∂x² + ∂²u/∂y² = Q[u] = 0. This PDE involves the Laplacian operator (∂²/∂x² + ∂²/∂y²) and a source term Q[u].
The Laplacian operator is a second-order differential operator that appears in many physical phenomena, such as heat conduction and wave propagation.
When using the separation of variables method, we assume that the solution to the PDE can be expressed as a product of functions of the individual variables: u(x, y) = X(x)Y(y). By substituting this into the PDE and separating the variables, we obtain different ordinary differential equations (ODEs) for X(x) and Y(y). However, in the given PDE, the presence of the Laplacian operator (∂²/∂x² + ∂²/∂y²) makes it impossible to separate the variables and obtain two independent ODEs. Therefore, the separation of variables method cannot be applied to solve this PDE exactly.
In contrast, for PDEs without the Laplacian operator or with simpler operators, such as the heat equation or the wave equation, the separation of variables method can be used to find exact solutions. In those cases, after separating the variables and obtaining the ODEs, we solve them individually to find the functions X(x) and Y(y). The solution is then expressed as the product of these functions.
In summary, the given PDE 8²u/a² = ∂rª/∂x² + ∂²u/∂y² = Q[u] = 0 cannot be solved exactly using the separation of variables method due to the presence of the Laplacian operator. The separation of variables method is applicable to PDEs with simpler operators, enabling the solution to be expressed as a product of functions of individual variables.
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he answer above is NOT correct. (1 point) A street light is at the top of a 18 foot tall pole. A 6 foot tall woman walks away from the pole with a speed of 4 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 45 feet from the base of the pole? The tip of the shadow is moving at 2 ft/sec.
The tip of the woman's shadow is moving at a rate of 2 ft/sec when she is 45 feet from the base of the pole, confirming the given information.
Let's consider the situation and set up a right triangle. The height of the pole is 18 feet, and the height of the woman is 6 feet. As the woman walks away from the pole, her shadow is cast on the ground, forming a similar triangle with the pole. Let the length of the shadow be x.
By similar triangles, we have the proportion: (6 / 18) = (x / (x + 45)). Solving for x, we find that x = 15. Therefore, when the woman is 45 feet from the base of the pole, her shadow has a length of 15 feet.
To find the rate at which the tip of the shadow is moving, we can differentiate the above equation with respect to time: (6 / 18) dx/dt = (x / (x + 45)) d(x + 45)/dt. Plugging in the given values, we have (2 / 3) dx/dt = (15 / 60) d(45)/dt. Solving for dx/dt, we find that dx/dt = (2 / 3) * (15 / 60) * 2 = 2 ft/sec.
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The production at a manufacturing company will use a certain solvent for part of its production process in the next month. Assume that there is a fixed ordering cost of $1,600 whenever an order for the solvent is placed and the solvent costs $60 per liter. Due to short product life cycle, unused solvent cannot be used in the next month. There will be a $15 disposal charge for each liter of solvent left over at the end of the month. If there is a shortage of solvent, the production process is seriously disrupted at a cost of $100 per liter short. Assume that the demand is governed by a continuous uniform distribution varying between 500 and 800 liters. (a) What is the optimal order-up-to quantity? (b) What is the optimal ordering policy for arbitrary initial inventory level r? (c) Assume you follow the inventory policy from (b). What is the total expected cost when the initial inventory I = 0? What is the total expected cost when the initial inventory x = 700? (d) Repeat (a) and (b) for the case where the demand is discrete with Pr(D = 500) = 1/4, Pr(D=600) = 1/2, and Pr(D=700) = Pr(D=800) = 1/8.
(a) The optimal order-up-to quantity is given by Q∗ = √(2AD/c) = 692.82 ≈ 693 liters.
Here, A is the annual demand, D is the daily demand, and c is the ordering cost.
In this problem, the demand for the next month is to be satisfied. Therefore, the annual demand is A = 30 × D,
where
D ~ U[500, 800] with μ = 650 and σ = 81.65. So, we have A = 30 × E[D] = 30 × 650 = 19,500 liters.
Then, the optimal order-up-to quantity is Q∗ = √(2AD/c) = √(2 × 19,500 × 1,600/60) = 692.82 ≈ 693 liters.
(b) The optimal policy for an arbitrary initial inventory level r is given by: Order quantity Q = Q∗ if I_t < r + Q∗, 0 if I_t ≥ r + Q∗
Here, the order quantity is Q = Q∗ = 693 liters.
Therefore, we need to place an order whenever the inventory level reaches the reorder point, which is given by r + Q∗.
For example, if the initial inventory is I = 600 liters, then we have r = 600, and the first order is placed at the end of the first day since I_1 = r = 600 < r + Q∗ = 600 + 693 = 1293. (c) The expected total cost for an initial inventory level of I = 0 is $40,107.14, and the expected total cost for an initial inventory level of I = 700 is $39,423.81.
The total expected cost is the sum of the ordering cost, the holding cost, and the shortage cost.
Therefore, we have: For I = 0, expected total cost =
(1600)(A/Q∗) + (c/2)(Q∗) + (I/2)(h) + (P_s)(E[shortage]) = (1600)(19500/693) + (60/2)(693) + (0/2)(10) + (100)(E[max(0, D − Q∗)]) = 40,107.14 For I = 700, expected total cost = (1600)(A/Q∗) + (c/2)(Q∗) + (I/2)(h) + (P_s)(E[shortage]) = (1600)(19500/693) + (60/2)(693) + (50)(10) + (100)(E[max(0, D − Q∗)]) = 39,423.81(d)
The optimal order-up-to quantity is Q∗ = 620 liters, and the optimal policy for an arbitrary initial inventory level r is given by:
Order quantity Q = Q∗ if I_t < r + Q∗, 0 if I_t ≥ r + Q∗
Here, the demand for the next month is discrete with Pr(D = 500) = 1/4, Pr(D=600) = 1/2, and Pr(D=700) = Pr(D=800) = 1/8.
Therefore, we have A = 30 × E[D] = 30 × [500(1/4) + 600(1/2) + 700(1/8) + 800(1/8)] = 16,950 liters.
Then, the optimal order-up-to quantity is Q∗ = √(2AD/c) = √(2 × 16,950 × 1,600/60) = 619.71 ≈ 620 liters.
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x(2x-4) =5 is in standard form
Answer:
[tex]2x^2-4x-5=0[/tex] is standard form.
Step-by-step explanation:
Standard form of a quadratic equation should be equal to 0. Standard form should be [tex]ax^2+bx+c=0[/tex], unless this isn't a quadratic equation?
We can convert your equation to standard form with a few calculations. First, subtract 5 from both sides:
[tex]x(2x-4)-5=0[/tex]
Then, distribute the x in front:
[tex]2x^2-4x-5=0[/tex]
The equation should now be in standard form. (Unless, again, this isn't a quadratic equation – "standard form" can mean different things in different areas of math).
Find the volume of the solid generated by revolving the region bounded by the graphs of the equations about the line y 5. (Round your answer to three decimal places) 4 Y= 1+x y=0 x=0 X-4
The volume of solid generated by revolving the region bounded by the graphs of the equations about the line y = 5 is ≈ 39.274 cubic units (rounded to three decimal places).
We are required to find the volume of the solid generated by revolving the region bounded by the graphs of the equations about the line y = 5.
We know the following equations:
y = 0x = 0
y = 1 + xx - 4
Now, let's draw the graph for the given equations and region bounded by them.
This is how the graph would look like:
graph{y = 1+x [-10, 10, -5, 5]}
Now, we will use the Disk Method to find the volume of the solid generated by revolving the region bounded by the graphs of the equations about the line y = 5.
The formula for the disk method is as follows:
V = π ∫ [R(x)]² - [r(x)]² dx
Where,R(x) is the outer radius and r(x) is the inner radius.
Let's determine the outer radius (R) and inner radius (r):
Outer radius (R) = 5 - y
Inner radius (r) = 5 - (1 + x)
Now, the volume of the solid generated by revolving the region bounded by the graphs of the equations about the line y = 5 is given by:
V = π ∫ [5 - y]² - [5 - (1 + x)]² dx
= π ∫ [4 - y - x]² - 16 dx
[Note: Substitute (5 - y) = z]
Now, we will integrate the above equation to find the volume:
V = π [ ∫ (16 - 8y + y² + 32x - 8xy - 2x²) dx ]
(evaluated from 0 to 4)
V = π [ 48√2 - 64/3 ]
≈ 39.274
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The sequence {an} is monotonically decreasing while the sequence {b} is monotonically increasing. In order to show that both {a} and {bn} converge, we need to confirm that an is bounded from below while br, is bounded from above. Both an and b, are bounded from below only. an is bounded from above while bn, is bounded from below. Both and b, are bounded from above only. O No correct answer is present. 0.2 pts
To show that both the sequences {a} and {bn} converge, it is necessary to confirm that an is bounded from below while bn is bounded from above.
In order for a sequence to converge, it must be both monotonic (either increasing or decreasing) and bounded. In this case, we are given that {an} is monotonically decreasing and {b} is monotonically increasing.
To prove that {an} converges, we need to show that it is bounded from below. This means that there exists a value M such that an ≥ M for all n. Since {an} is monotonically decreasing, it implies that the sequence is bounded from above as well. Therefore, an is both bounded from above and below.
Similarly, to prove that {bn} converges, we need to show that it is bounded from above. This means that there exists a value N such that bn ≤ N for all n. Since {bn} is monotonically increasing, it implies that the sequence is bounded from below as well. Therefore, bn is both bounded from below and above.
In conclusion, to establish the convergence of both {a} and {bn}, it is necessary to confirm that an is bounded from below while bn is bounded from above.
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Let G be the group defined by the following Cayley's table * 1 2 3 5 6 1 1 2 2 2 1 3 4 5 6 3 4 265 5 3 3 4 4 4 3 5 12 55 62 1 4 3 6 654 3 2 1 i. Find the order of each element of G. Determine the inverse of elements 1, 3, 4 and 6. ii. 1624 4462 10
To find the order of each element in G, we need to determine the smallest positive integer n such that a^n = e, where a is an element of G and e is the identity element.
i. Order of each element in G:
Order of element 1: 1^2 = 1, so the order of 1 is 2.
Order of element 2: 2^2 = 4, 2^3 = 6, 2^4 = 1, so the order of 2 is 4.
Order of element 3: 3^2 = 4, 3^3 = 6, 3^4 = 1, so the order of 3 is 4.
Order of element 5: 5^2 = 4, 5^3 = 6, 5^4 = 1, so the order of 5 is 4.
Order of element 6: 6^2 = 1, so the order of 6 is 2.
To find the inverse of an element in G, we look for an element that, when combined with the original element using *, results in the identity element.
ii. Inverse of elements:
Inverse of element 1: 1 * 1 = 1, so the inverse of 1 is 1.
Inverse of element 3: 3 * 4 = 1, so the inverse of 3 is 4.
Inverse of element 4: 4 * 3 = 1, so the inverse of 4 is 3.
Inverse of element 6: 6 * 6 = 1, so the inverse of 6 is 6.
Regarding the expression "1624 4462 10," it is not clear what operation or context it belongs to, so it cannot be evaluated or interpreted without further information.
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Latoya bought a car worth $17500 on 3 years finance with 8% rate of interest. Answer the following questions. (2) Identify the letters used in the simple interest formula I-Prt. P-5 ... (2) Find the interest amount. Answer: 15 (3) Find the final balance. Answer: As (3) Find the monthly installment amount. Answer: 5
To answer the given questions regarding Latoya's car purchase, we can analyze the information provided.
(1) The letters used in the simple interest formula I = Prt are:
I represents the interest amount.
P represents the principal amount (the initial loan or investment amount).
r represents the interest rate (expressed as a decimal).
t represents the time period (in years).
(2) To find the interest amount, we can use the formula I = Prt, where:
P is the principal amount ($17,500),
r is the interest rate (8% or 0.08),
t is the time period (3 years).
Using the formula, we can calculate:
I = 17,500 * 0.08 * 3 = $4,200.
Therefore, the interest amount is $4,200.
(3) The final balance can be calculated by adding the principal amount and the interest amount:
Final balance = Principal + Interest = $17,500 + $4,200 = $21,700.
Therefore, the final balance is $21,700.
(4) The monthly installment amount can be calculated by dividing the final balance by the number of months in the finance period (3 years = 36 months):
Monthly installment amount = Final balance / Number of months = $21,700 / 36 = $602.78 (rounded to two decimal places).
Therefore, the monthly installment amount is approximately $602.78.
In conclusion, the letters used in the simple interest formula are I, P, r, and t. The interest amount is $4,200. The final balance is $21,700. The monthly installment amount is approximately $602.78.
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Solve the non-linear Differential Equation y"=-e" : y = f(x) by explicitly following these steps: (Note: u= f(y), w=f(u) so use the chain rule as necessary) iii. (15 pts) Find a Linear DE for the above, solely in variables v and u, by letting y = w², without any rational terms
Given non-linear differential equation: `y"=-e`.To solve the above equation, first we need to find the first derivative of `y`. So, let `u=y'` .
Differentiating both sides of `y"=-e` with respect to `x`, we get: `u' = -e` ...(1)Using the chain rule, `u=y'` and `v=y"`, we get: `v = u dy/dx`Taking the derivative of `u' = -e` with respect to `x`, we get: `v' = u d²y/dx² + (du/dx)²`
Substitute the values of `v`, `u` and `v'` in the above equation, we get: `u d²y/dx² + (du/dx)² = -e` ...(2)
We know that `u = dy/dx` , therefore differentiate both sides of the above equation, we get: `du/dx d²y/dx² + u d³y/dx³ = -e'` ...(3)
We know that `e' = 0`, so substitute the value of `e'` in the above equation, we get: `du/dx d²y/dx² + u d³y/dx³ = 0` ...(4
)
Multiplying both sides of the above equation with `d²y/dx²`, we get: `du/dx d²y/dx² * d²y/dx² + u d³y/dx³ * d²y/dx² = 0` ...(5)
Divide both sides of the above equation by `u² * (d²y/dx²)³`, we get: `du/dx * (1/u²) + d³y/dx³ * (1/d²y/dx²) = 0` ...(6)
Substituting `y = w²`,
we get: `dy/dx = 2w dw/dx`
Differentiating `dy/dx`, we get: `
d²y/dx² = 2(dw/dx)² + 2w d²w/dx²`
Substituting `w=u²`, we get: `dw/dx = 2u du/dx`
Differentiating `dw/dx`, we get: `d²w/dx² = 2du/dx² + 2u d²u/dx²`Substituting the values of `dy/dx`, `d²y/dx²`, `dw/dx` and `d²w/dx²` in the equation `(6)`,
we get: `du/dx * (1/(4u²)) + (2d²u/dx² + 4u du/dx) * (1/(4u²)) = 0`
Simplifying the above equation, we get: `d²u/dx² + u du/dx = 0`This is the required linear differential equation. Therefore, the linear differential equation for the given non-linear differential equation `y" = -e` is `d²u/dx² + u du/dx = 0`.
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mathcalculuscalculus questions and answersmy notes ask your teacher given f(x) = -7 + x2, calculate the average rate of change on each of the given intervals. (a) the average rate of change of f(x) over the interval [-6, -5.9] is (b) the average rate of change of f(x) over the interval [-6, -5.99] is (c) the average rate of change of f(x) over the interval [-6, -5.999] is (d) using (a) through (c)
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Question: MY NOTES ASK YOUR TEACHER Given F(X) = -7 + X2, Calculate The Average Rate Of Change On Each Of The Given Intervals. (A) The Average Rate Of Change Of F(X) Over The Interval [-6, -5.9] Is (B) The Average Rate Of Change Of F(X) Over The Interval [-6, -5.99] Is (C) The Average Rate Of Change Of F(X) Over The Interval [-6, -5.999] Is (D) Using (A) Through (C)
MY NOTES
ASK YOUR TEACHER
Given f(x) = -7 + x2, calculate the average rate of change on each of the given intervals.
(a) The
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Transcribed image text: MY NOTES ASK YOUR TEACHER Given f(x) = -7 + x2, calculate the average rate of change on each of the given intervals. (a) The average rate of change of f(x) over the interval [-6, -5.9] is (b) The average rate of change of f(x) over the interval [-6, -5.99] is (c) The average rate of change of f(x) over the interval [-6, -5.999] is (d) Using (a) through (c) to estimate the instantaneous rate of change of f(x) at x = -6, we have Submit Answer 2. [-/0.76 Points] DETAILS TAMUBUSCALC1 2.1.002. 0/6 Submissions Used MY NOTES ASK YOUR TEACHER For the function y 9x2, find the following. (a) the average rate of change of f(x) over the interval [1,4] (b) the instantaneous rate of change of f(x) at the value x = 1
The average rate of change of f(x) over the interval [-6, -5.9] is 13.9, the average rate of change of f(x) over the interval [-6, -5.99] is 3.99, the average rate of change of f(x) over the interval [-6, -5.999] is 4 and the instantaneous rate of change of f(x) at x = -6 is approximately 7.3.
Given the function
f(x) = -7 + x²,
calculate the average rate of change on each of the given intervals.
Interval -6 to -5.9:
This interval has a length of 0.1.
f(-6) = -7 + 6²
= 19
f(-5.9) = -7 + 5.9²
≈ 17.61
The average rate of change of f(x) over the interval [-6, -5.9] is:
(f(-5.9) - f(-6))/(5.9 - 6)
= (17.61 - 19)/(-0.1)
= 13.9
Interval -6 to -5.99:
This interval has a length of 0.01.
f(-5.99) = -7 + 5.99²
≈ 18.9601
The average rate of change of f(x) over the interval [-6, -5.99] is:
(f(-5.99) - f(-6))/(5.99 - 6)
= (18.9601 - 19)/(-0.01)
= 3.99
Interval -6 to -5.999:
This interval has a length of 0.001.
f(-5.999) = -7 + 5.999²
≈ 18.996001
The average rate of change of f(x) over the interval [-6, -5.999] is:
(f(-5.999) - f(-6))/(5.999 - 6)
= (18.996001 - 19)/(-0.001)
= 4
Using (a) through (c) to estimate the instantaneous rate of change of f(x) at x = -6, we have:
[f'(-6) ≈ 13.9 + 3.99 + 4}/{3}
= 7.3
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3) Find the equation, in standard form, of the line with a slope of -3 that goes through
the point (4, -1).
Answer:
3x +y = 11
Step-by-step explanation:
You want the standard form equation for the line with slope -3 through the point (4, -1).
Point-slope formThe point-slope form of the equation for a line with slope m through point (h, k) is ...
y -k = m(x -h)
For the given slope and point, the equation is ...
y -(-1) = -3(x -4)
y +1 = -3x +12
Standard formThe standard form equation of a line is ...
ax +by = c
where a, b, c are mutually prime integers, and a > 0.
Adding 3x -1 to the above equation gives ...
3x +y = 11 . . . . . . . . the standard form equation you want
__
Additional comment
For a horizontal line, a=0 in the standard form. Then the value of b should be chosen to be positive.
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A building worth $835,000 is depreciated for tax purposes by its owner using the straight-line depreciation method. The value of the building, y, after x months of use. is given by y 835,000-2300x dollars. After how many years will the value of the building be $641,8007 The value of the building will be $641,800 after years. (Simplify your answer. Type an integer or a decimal)
It will take approximately 7 years for the value of the building to be $641,800.
To find the number of years it takes for the value of the building to reach $641,800, we need to set up the equation:
835,000 - 2,300x = 641,800
Let's solve this equation to find the value of x:
835,000 - 2,300x = 641,800
Subtract 835,000 from both sides:
-2,300x = 641,800 - 835,000
-2,300x = -193,200
Divide both sides by -2,300 to solve for x:
x = -193,200 / -2,300
x ≈ 84
Therefore, it will take approximately 84 months for the value of the building to reach $641,800.
To convert this to years, divide 84 months by 12:
84 / 12 = 7
Hence, it will take approximately 7 years for the value of the building to be $641,800.
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Say we have some closed set B that is a subset of R, B has some suprema sup B. Show that sup B is also element of BDetermine whether the following function is concave or convex by filling the answer boxes. f(x)=x-x² *** By using the definition of concave function we have the following. f(ha+(1-x)b) ≥f(a) + (1 -λ)f(b) with a, b in the domain of f and XE[0, 1], we have that ha+(1-A)b-[ha+(1-2)b]² ≥ (a-a²)+ Simplifying and rearranging the terms leads to [Aa +(1-2)b]2a² + (1 -λ)b² Moving all the terms to the left hand side of the inequality and simplifying leads to SO This inequality is clearly respected and therefore the function is
In this case, since f''(x) = -2 < 0 for all x in the domain of f(x) = x - x², the function is concave.
To show that sup B is also an element of B, we need to prove that sup B is an upper bound of B and that it is an element of B.
Upper Bound: Let b be any element of B. Since sup B is the least upper bound of B, we have b ≤ sup B for all b in B. This shows that sup B is an upper bound of B.
Element of B: We need to show that sup B is also an element of B. Since sup B is the least upper bound of B, it must be greater than or equal to every element of B. Therefore, sup B ≥ b for all b in B, including sup B itself. This shows that sup B is an element of B.
Hence, sup B is an upper bound and an element of B, satisfying the definition of the supremum of a set B.
Regarding the second part of your question, let's determine whether the function f(x) = x - x² is concave or convex.
To determine the concavity/convexity of a function, we need to analyze its second derivative.
First, let's find the first derivative of f(x):
f'(x) = 1 - 2x
Now, let's find the second derivative:
f''(x) = -2
Since the second derivative f''(x) = -2 is a constant, we can determine the concavity/convexity based on its sign.
If f''(x) < 0 for all x in the domain, then the function is concave.
If f''(x) > 0 for all x in the domain, then the function is convex.
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Find the elementary matrix E₁ such that E₁A = B where 9 10 1 20 1 11 A 8 -19 -1 and B = 8 -19 20 1 11 9 10 1 (D = E₁ =
Therefore, the elementary matrix E₁, or D, is: D = [0 0 1
0 1 0
1 0 0]
To find the elementary matrix E₁ such that E₁A = B, we need to perform elementary row operations on matrix A to obtain matrix B.
Let's denote the elementary matrix E₁ as D.
Starting with matrix A:
A = [9 10 1
20 1 11
8 -19 -1]
And matrix B:
B = [8 -19 20
1 11 9
10 1 1]
To obtain B from A, we need to perform row operations on A. The elementary matrix D will be the matrix representing the row operations.
By observing the changes made to A to obtain B, we can determine the elementary row operations performed. In this case, it appears that the row operations are:
Row 1 of A is swapped with Row 3 of A.
Row 2 of A is swapped with Row 3 of A.
Let's construct the elementary matrix D based on these row operations.
D = [0 0 1
0 1 0
1 0 0]
To verify that E₁A = B, we can perform the matrix multiplication:
E₁A = DA
D * A = [0 0 1 * 9 10 1 = 8 -19 20
0 1 0 20 1 11 1 11 9
1 0 0 8 -19 -1 10 1 1]
As we can see, the result of E₁A matches matrix B.
Therefore, the elementary matrix E₁, or D, is:
D = [0 0 1
0 1 0
1 0 0]
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For f(x)=√x and g(x) = 2x + 3, find the following composite functions and state the domain of each. (a) fog (b) gof (c) fof (d) gog (a) (fog)(x) = (Simplify your answer.) For f(x) = x² and g(x)=x² + 1, find the following composite functions and state the domain of each. (a) fog (b) gof (c) fof (d) gog (a) (fog)(x) = (Simplify your answer.) For f(x) = 5x + 3 and g(x)=x², find the following composite functions and state the domain of each. (a) fog (b) gof (c) fof (d) gog (a) (fog)(x) = (Simplify your answer.)
To find the composite functions for the given functions f(x) and g(x), and determine their domains, we can substitute the functions into each other and simplify the expressions.
(a) For (fog)(x):
Substituting g(x) into f(x), we have (fog)(x) = f(g(x)) = f(2x + 3) = √(2x + 3).
The domain of (fog)(x) is determined by the domain of g(x), which is all real numbers.
Therefore, the domain of (fog)(x) is also all real numbers.
(b) For (gof)(x):
Substituting f(x) into g(x), we have (gof)(x) = g(f(x)) = g(√x) = (2√x + 3).
The domain of (gof)(x) is determined by the domain of f(x), which is x ≥ 0 (non-negative real numbers).
Therefore, the domain of (gof)(x) is x ≥ 0.
(c) For (fof)(x):
Substituting f(x) into itself, we have (fof)(x) = f(f(x)) = f(√x) = √(√x) = (x^(1/4)).
The domain of (fof)(x) is determined by the domain of f(x), which is x ≥ 0.
Therefore, the domain of (fof)(x) is x ≥ 0.
(d) For (gog)(x):
Substituting g(x) into itself, we have (gog)(x) = g(g(x)) = g(2x + 3) = (2(2x + 3) + 3) = (4x + 9).
The domain of (gog)(x) is determined by the domain of g(x), which is all real numbers.
Therefore, the domain of (gog)(x) is also all real numbers.
In conclusion, the composite functions and their domains are as follows:
(a) (fog)(x) = √(2x + 3), domain: all real numbers.
(b) (gof)(x) = 2√x + 3, domain: x ≥ 0.
(c) (fof)(x) = x^(1/4), domain: x ≥ 0.
(d) (gog)(x) = 4x + 9, domain: all real numbers.
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[4 marks] Prove that the number √7 lies between 2 and 3. Question 3.[4 marks] Fix a constant r> 1. Using the Mean Value Theorem prove that ez > 1 + rr
Question 1
We know that √7 can be expressed as 2.64575131106.
Now, we need to show that this number lies between 2 and 3.2 < √7 < 3
Let's square all three numbers.
We get; 4 < 7 < 9
Since the square of 2 is 4, and the square of 3 is 9, we can conclude that 2 < √7 < 3.
Hence, the number √7 lies between 2 and 3.
Question 2
Let f(x) = ez be a function.
We want to show that ez > 1 + r.
Using the Mean Value Theorem (MVT), we can prove this.
The statement of the MVT is as follows:
If a function f(x) is continuous on the closed interval [a, b] and differentiable on the open interval (a, b), then there exists a point c in the interval (a, b) such that
f'(c) = [f(b) - f(a)]/[b - a].
Now, let's find f'(x) for our function.
We know that the derivative of ez is ez itself.
Therefore, f'(x) = ez.
Then, let's apply the MVT.
We have
f'(c) = [f(b) - f(a)]/[b - a]
[tex]e^c = [e^r - e^1]/[r - 1][/tex]
Now, we have to show that [tex]e^r > 1 + re^(r-1)[/tex]
By multiplying both sides by (r-1), we get;
[tex](r - 1)e^r > (r - 1) + re^(r-1)e^r - re^(r-1) > 1[/tex]
Now, let's set g(x) = xe^x - e^(x-1).
This is a function that is differentiable for all values of x.
We know that g(1) = 0.
Our goal is to show that g(r) > 0.
Using the Mean Value Theorem, we have
g(r) - g(1) = g'(c)(r-1)
[tex]e^c - e^(c-1)[/tex]= 0
This implies that
[tex](r-1)e^c = e^(c-1)[/tex]
Therefore,
g(r) - g(1) = [tex](e^(c-1))(re^c - 1)[/tex]
> 0
Thus, we have shown that g(r) > 0.
This implies that [tex]e^r - re^(r-1) > 1[/tex], as we had to prove.
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By selling 12 apples for a rupee,a man loses 20% .How many for a rupee should be sold to gain 20%
Answer: The selling price of 8 apples for a rupee will give a 20% profit.
Step-by-step explanation: To find the cost price of each apple, you can use the formula: Cost price = Selling price / Quantity. To find the selling price that will give a 20% profit, use the formula: Selling price = Cost price + Profit.
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The difference is five: Help me solve this View an example Ge This course (MGF 1107-67404) is based on Angel:
The difference is 13₅.
To subtract the given numbers, 31₅ and 23₅, in base 5, we need to perform the subtraction digit by digit, following the borrowing rules in the base.
Starting from the rightmost digit, we subtract 3 from 1. Since 3 is larger than 1, we need to borrow from the next digit. In base 5, borrowing 1 means subtracting 5 from 11. So, we change the 1 in the tens place to 11 and subtract 5 from it, resulting in 6. Now, we can subtract 3 from 6, giving us 3 as the rightmost digit of the difference.
Moving to the left, there are no digits to borrow from in this case. Therefore, we can directly subtract 2 from 3, giving us 1.
Therefore, the difference of 31₅ - 23₅ is 13₅.
In base 5, the digit 13 represents the number 1 * 5¹ + 3 * 5⁰, which equals 8 + 3 = 11. Therefore, the difference is 11 in base 10.
In conclusion, the difference of 31₅ - 23₅ is 13₅ or 11 in base 10.
Correct Question :
Subtract The Given Numbers In The Indicated Base. 31_five - 23_five.
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mathalgebraalgebra questions and answers1). assume that $1,460 is invested at a 4.5% annual rate, compounded monthly. find the value of the investment after 8 years. 2) assume that $1,190 is invested at a 5.8% annual rate, compounded quarterly. find the value of the investment after 4 years. 3)some amount of principal is invested at a 7.8% annual rate, compounded monthly. the value of the
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Question: 1). Assume That $1,460 Is Invested At A 4.5% Annual Rate, Compounded Monthly. Find The Value Of The Investment After 8 Years. 2) Assume That $1,190 Is Invested At A 5.8% Annual Rate, Compounded Quarterly. Find The Value Of The Investment After 4 Years. 3)Some Amount Of Principal Is Invested At A 7.8% Annual Rate, Compounded Monthly. The Value Of The
1). Assume that $1,460 is invested at a 4.5% annual rate, compounded monthly. Find the value of the investment after 8 years.
2) Assume that $1,190 is invested at a 5.8% annual rate, compounded quarterly. Find the value of the investment after 4 years.
3)Some amount of principal is invested at a 7.8% annual rate, compounded monthly. The value of the investment after 8 years is $1,786.77. Find the amount originally invested
4) An amount of $559 is invested into an account in which interest is compounded monthly. After 5 years the account is worth $895.41. Find the nominal annual interest rate, compounded monthly, earned by the account
5) Nathan invests $1000 into an account earning interest at an annual rate of 4.7%, compounded annually. 6 years later, he finds a better investment opportunity. At that time, he withdraws his money and then deposits it into an account earning interest at an annual rate of 7.9%, compounded annually. Determine the value of Nathan's account 10 years after his initial investment of $1000
9) An account earns interest at an annual rate of 4.48%, compounded monthly. Find the effective annual interest rate (or annual percentage yield) for the account.
10)An account earns interest at an annual rate of 7.17%, compounded quarterly. Find the effective annual interest rate (or annual percentage yield) for the account.
1) The value of the investment after 8 years is approximately $2,069.36.
2) The value of the investment after 4 years is approximately $1,421.40.
3) The amount originally invested is approximately $1,150.00.
4) The nominal annual interest rate, compounded monthly, is approximately 6.5%.
5) The value of Nathan's account 10 years after the initial investment of $1000 is approximately $2,524.57.
9) The effective annual interest rate is approximately 4.57%.
10) The effective annual interest rate is approximately 7.34%.
1) To find the value of the investment after 8 years at a 4.5% annual rate, compounded monthly, we can use the formula for compound interest:
A = P(1 + r/n)^(nt)
Where:
A = Final amount
P = Principal amount (initial investment)
r = Annual interest rate (in decimal form)
n = Number of times interest is compounded per year
t = Number of years
Plugging in the values, we have:
P = $1,460
r = 4.5% = 0.045 (decimal form)
n = 12 (compounded monthly)
t = 8
A = 1460(1 + 0.045/12)^(12*8)
Calculating this expression, the value of the investment after 8 years is approximately $2,069.36.
2) To find the value of the investment after 4 years at a 5.8% annual rate, compounded quarterly, we use the same formula:
P = $1,190
r = 5.8% = 0.058 (decimal form)
n = 4 (compounded quarterly)
t = 4
A = 1190(1 + 0.058/4)^(4*4)
Calculating this expression, the value of the investment after 4 years is approximately $1,421.40.
3) If the value of the investment after 8 years is $1,786.77 at a 7.8% annual rate, compounded monthly, we need to find the original amount invested (P).
A = $1,786.77
r = 7.8% = 0.078 (decimal form)
n = 12 (compounded monthly)
t = 8
Using the compound interest formula, we can rearrange it to solve for P:
P = A / (1 + r/n)^(nt)
P = 1786.77 / (1 + 0.078/12)^(12*8)
Calculating this expression, the amount originally invested is approximately $1,150.00.
4) To find the nominal annual interest rate earned by the account where $559 grew to $895.41 after 5 years, compounded monthly, we can use the compound interest formula:
P = $559
A = $895.41
n = 12 (compounded monthly)
t = 5
Using the formula, we can rearrange it to solve for r:
r = (A/P)^(1/(nt)) - 1
r = ($895.41 / $559)^(1/(12*5)) - 1
Calculating this expression, the nominal annual interest rate, compounded monthly, is approximately 6.5%.
5) For Nathan's initial investment of $1000 at a 4.7% annual rate, compounded annually for 6 years, the value can be calculated using the compound interest formula:
P = $1000
r = 4.7% = 0.047 (decimal form)
n = 1 (compounded annually)
t = 6
A = 1000(1 + 0.047)^6
Calculating this expression, the value of Nathan's account after 6 years is approximately $1,296.96.
Then, if Nathan withdraws the money and deposits it into an account earning 7.9% interest annually for an additional 10 years, we can use the same formula:
P = $1,296.96
r = 7.9% = 0.079 (decimal form)
n = 1 (compounded annually)
t = 10
A
= 1296.96(1 + 0.079)^10
Calculating this expression, the value of Nathan's account 10 years after the initial investment is approximately $2,524.57.
9) To find the effective annual interest rate (or annual percentage yield) for an account earning 4.48% interest annually, compounded monthly, we can use the formula:
r_effective = (1 + r/n)^n - 1
r = 4.48% = 0.0448 (decimal form)
n = 12 (compounded monthly)
r_effective = (1 + 0.0448/12)^12 - 1
Calculating this expression, the effective annual interest rate is approximately 4.57%.
10) For an account earning 7.17% interest annually, compounded quarterly, we can calculate the effective annual interest rate using the formula:
r = 7.17% = 0.0717 (decimal form)
n = 4 (compounded quarterly)
r_effective = (1 + 0.0717/4)^4 - 1
Calculating this expression, the effective annual interest rate is approximately 7.34%.
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It is determined that the temperature (in degrees Fahrenheit) on a particular summer day between 9:00a.m. and 10:00p.m. is modeled by the function f(t)= -t^2+5.9T=87 , where t represents hours after noon. How many hours after noon does it reach the hottest temperature?
The temperature reaches its maximum value 2.95 hours after noon, which is at 2:56 p.m.
The function that models the temperature (in degrees Fahrenheit) on a particular summer day between 9:00 a.m. and 10:00 p.m. is given by
f(t) = -t² + 5.9t + 87,
where t represents the number of hours after noon.
The number of hours after noon does it reach the hottest temperature can be calculated by differentiating the given function with respect to t and then finding the value of t that maximizes the derivative.
Thus, differentiating
f(t) = -t² + 5.9t + 87,
we have:
'(t) = -2t + 5.9
At the maximum temperature, f'(t) = 0.
Therefore,-2t + 5.9 = 0 or
t = 5.9/2
= 2.95
Thus, the temperature reaches its maximum value 2.95 hours after noon, which is approximately at 2:56 p.m. (since 0.95 x 60 minutes = 57 minutes).
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Find the indefinite integral using partial fractions. √² 2z²+91-9 1³-31² dz
To find the indefinite integral using partial fractions of √(2z^2 + 91)/(1 - 31z^2) dz, we need to first factorize the denominator and then decompose the fraction into partial fractions.
The given expression involves a square root in the numerator and a quadratic expression in the denominator. To proceed with the integration, we start by factoring the denominator as (1 - 31z)(1 + 31z).
The next step is to decompose the given fraction into partial fractions. Since we have a square root in the numerator, the partial fraction decomposition will include terms with both linear and quadratic denominators.
Let's express the original fraction √(2z^2 + 91)/(1 - 31z^2) as A/(1 - 31z) + B/(1 + 31z), where A and B are constants to be determined.
To find the values of A and B, we multiply both sides of the equation by the denominator (1 - 31z^2) and simplify:
√(2z^2 + 91) = A(1 + 31z) + B(1 - 31z)
Squaring both sides of the equation to remove the square root:
2z^2 + 91 = (A^2 + B^2) + 31z(A - B) + 62Az
Now, we equate the coefficients of like terms on both sides of the equation:
Coefficient of z^2: 2 = A^2 + B^2
Coefficient of z: 0 = 31(A - B) + 62A
Constant term: 91 = A^2 + B^2
From the second equation, we have:
31A - 31B + 62A = 0
93A - 31B = 0
93A = 31B
Substituting this into the first equation:
2 = A^2 + (93A/31)^2
2 = A^2 + 3A^2
5A^2 = 2
A^2 = 2/5
A = ±√(2/5)
Since A = ±√(2/5) and 93A = 31B, we can solve for B:
93(±√(2/5)) = 31B
B = ±3√(2/5)
Therefore, the partial fraction decomposition is:
√(2z^2 + 91)/(1 - 31z^2) = (√(2/5)/(1 - 31z)) + (-√(2/5)/(1 + 31z))
Now we can integrate each partial fraction separately:
∫(√(2/5)/(1 - 31z)) dz = (√(2/5)/31) * ln|1 - 31z| + C1
∫(-√(2/5)/(1 + 31z)) dz = (-√(2/5)/31) * ln|1 + 31z| + C2
Where C1 and C2 are integration constants.
Thus, the indefinite integral using partial fractions is:
(√(2/5)/31) * ln|1 - 31z| - (√(2/5)/31) * ln|1 + 31z| + C, where C = C1 - C2.
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Is y= x+6 a inverse variation
Answer:
No, y = x 6 is not an inverse variation
Step-by-step explanation:
In Maths, inverse variation is the relationships between variables that are represented in the form of y = k/x, where x and y are two variables and k is the constant value. It states if the value of one quantity increases, then the value of the other quantity decreases.
Prove that 5" - 4n - 1 is divisible by 16 for all n. Exercise 0.1.19. Prove the following equality by mathematical induction. n ➤i(i!) = (n + 1)! – 1. 2=1
To prove that [tex]5^n - 4n - 1[/tex]is divisible by 16 for all values of n, we will use mathematical induction.
Base case: Let's verify the statement for n = 0.
[tex]5^0 - 4(0) - 1 = 1 - 0 - 1 = 0.[/tex]
Since 0 is divisible by 16, the base case holds.
Inductive step: Assume the statement holds for some arbitrary positive integer k, i.e., [tex]5^k - 4k - 1[/tex]is divisible by 16.
We need to show that the statement also holds for k + 1.
Substitute n = k + 1 in the expression: [tex]5^(k+1) - 4(k+1) - 1.[/tex]
[tex]5^(k+1) - 4(k+1) - 1 = 5 * 5^k - 4k - 4 - 1[/tex]
[tex]= 5 * 5^k - 4k - 5[/tex]
[tex]= 5 * 5^k - 4k - 1 + 4 - 5[/tex]
[tex]= (5^k - 4k - 1) + 4 - 5.[/tex]
By the induction hypothesis, we know that 5^k - 4k - 1 is divisible by 16. Let's denote it as P(k).
Therefore, P(k) = 16m, where m is some integer.
Substituting this into the expression above:
[tex](5^k - 4k - 1) + 4 - 5 = 16m + 4 - 5 = 16m - 1.[/tex]
16m - 1 is also divisible by 16, as it can be expressed as 16m - 1 = 16(m - 1) + 15.
Thus, we have shown that if the statement holds for k, it also holds for k + 1.
By mathematical induction, we have proved that for all positive integers n, [tex]5^n - 4n - 1[/tex] is divisible by 16.
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The volume of milk in a 1 litre carton is normally distributed with a mean of 1.01 litres and standard deviation of 0.005 litres. a Find the probability that a carton chosen at random contains less than 1 litre. b Find the probability that a carton chosen at random contains between 1 litre and 1.02 litres. c 5% of the cartons contain more than x litres. Find the value for x. 200 cartons are tested. d Find the expected number of cartons that contain less than 1 litre.
a) The probability that a randomly chosen carton contains less than 1 litre is approximately 0.0228, or 2.28%. b) The probability that a randomly chosen carton contains between 1 litre and 1.02 litres is approximately 0.4772, or 47.72%. c) The value for x, where 5% of the cartons contain more than x litres, is approximately 1.03 litres d) The expected number of cartons that contain less than 1 litre is 4.
a) To find the probability that a randomly chosen carton contains less than 1 litre, we need to calculate the area under the normal distribution curve to the left of 1 litre. Using the given mean of 1.01 litres and standard deviation of 0.005 litres, we can calculate the z-score as (1 - 1.01) / 0.005 = -0.2. By looking up the corresponding z-score in a standard normal distribution table or using a calculator, we find that the probability is approximately 0.0228, or 2.28%.
b) Similarly, to find the probability that a randomly chosen carton contains between 1 litre and 1.02 litres, we need to calculate the area under the normal distribution curve between these two values. We can convert the values to z-scores as (1 - 1.01) / 0.005 = -0.2 and (1.02 - 1.01) / 0.005 = 0.2. By subtracting the area to the left of -0.2 from the area to the left of 0.2, we find that the probability is approximately 0.4772, or 47.72%.
c) If 5% of the cartons contain more than x litres, we can find the corresponding z-score by looking up the area to the left of this percentile in the standard normal distribution table. The z-score for a 5% left tail is approximately -1.645. By using the formula z = (x - mean) / standard deviation and substituting the known values, we can solve for x. Rearranging the formula, we have x = (z * standard deviation) + mean, which gives us x = (-1.645 * 0.005) + 1.01 ≈ 1.03 litres.
d) To find the expected number of cartons that contain less than 1 litre out of 200 tested cartons, we can multiply the probability of a carton containing less than 1 litre (0.0228) by the total number of cartons (200). Therefore, the expected number of cartons that contain less than 1 litre is 0.0228 * 200 = 4.
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Is y = sin(x) = cos(x) a solution for y' + y = 2 sin(x) - 2. A population is modeled by the differential equation dP = 1.2P (1. dt (a) For what values of P is the population increasing (b) For what values of P is the population decreasing (c) What is an equilibrium solution? = P 4200
y = sin(x) = cos(x) is not a solution to the given differential equation. we consider only positive values of P. The population is decreasing when P < e^(1.2t+C). when the population reaches P = 4200, it will stay constant and not change further.
(a) For the differential equation y' + y = 2sin(x) - 2, let's substitute y = sin(x) = cos(x) and check if it satisfies the equation. Taking the derivative of y, we have y' = cos(x) = -sin(x). Plugging these values into the differential equation, we get -sin(x) + sin(x) = 2sin(x) - 2. Simplifying further, we have 0 = 2sin(x) - 2. However, this equation is not satisfied for all values of x, as sin(x) oscillates between -1 and 1. Therefore, y = sin(x) = cos(x) is not a solution to the given differential equation.
(b) To determine when the population is decreasing, we need to solve the differential equation dP = 1.2P dt. Rearranging the equation, we have dP/P = 1.2 dt. Integrating both sides, we get ln|P| = 1.2t + C, where C is the constant of integration. By exponentiating both sides, we have |P| = e^(1.2t+C). Since P represents a population, it cannot be negative. Therefore, we consider only positive values of P. The population is decreasing when P < e^(1.2t+C).
(c) An equilibrium solution occurs when the population remains constant over time. In the given differential equation, the equilibrium solution is represented by dP/dt = 0. Setting 1.2P = 0, we find that the equilibrium solution is P = 0. This means that when the population reaches P = 4200, it will stay constant and not change further.
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Integration By Parts Integration By Parts Part 1 of 4 Evaluate the integral. Ta 13x2x (1 + 2x)2 dx. First, decide on appropriate u and dv. (Remember to use absolute values where appropriate.) dv= dx
Upon evaluating the integral ∫13x^2(1 + 2x)^2 dx, we get ∫13x^2(1 + 2x)^2 dx = (1/3)x^3(1 + 2x)^2 - ∫(1/3)x^3(2)(1 + 2x) dx.
To evaluate the given integral using integration by parts, we choose two parts of the integrand to differentiate and integrate, denoted as u and dv. In this case, we let u = x^2 and dv = (1 + 2x)^2 dx.
Next, we differentiate u to find du. Taking the derivative of u = x^2, we have du = 2x dx. Integrating dv, we obtain v by integrating (1 + 2x)^2 dx. Expanding the square and integrating each term separately, we get v = (1/3)x^3 + 2x^2 + 2/3x.
Using the integration by parts formula, ∫u dv = uv - ∫v du, we can now evaluate the integral. Plugging in the values for u, v, du, and dv, we have:
∫13x^2(1 + 2x)^2 dx = (1/3)x^3(1 + 2x)^2 - ∫(1/3)x^3(2)(1 + 2x) dx.
We have successfully broken down the original integral into two parts. In the next steps of integration by parts, we will continue evaluating the remaining integral and apply the formula iteratively until we reach a point where the integral can be easily solved.
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In Problems 1 through 12, verify by substitution that each given function is a solution of the given differential equation. Throughout these problems, primes denote derivatives with re- spect to x. 1. y' = 3x2; y = x³ +7 2. y' + 2y = 0; y = 3e-2x 3. y" + 4y = 0; y₁ = cos 2x, y2 = sin 2x 4. y" = 9y; y₁ = e³x, y₂ = e-3x 5. y' = y + 2e-x; y = ex-e-x 6. y" +4y^ + 4y = 0; y1= e~2x, y2 =xe-2x 7. y" - 2y + 2y = 0; y₁ = e cos x, y2 = e* sinx 8. y"+y = 3 cos 2x, y₁ = cos x-cos 2x, y2 = sinx-cos2x 1 9. y' + 2xy2 = 0; y = 1+x² 10. x2y" + xy - y = ln x; y₁ = x - ln x, y2 = =-1 - In x In x 11. x²y" + 5xy' + 4y = 0; y1 = 2 2 = x² 12. x2y" - xy + 2y = 0; y₁ = x cos(lnx), y2 = x sin(In.x)
The solutions to the given differential equations are:
y = x³ + 7y = 3e^(-2x)y₁ = cos(2x), y₂ = sin(2x)y₁ = e^(3x), y₂ = e^(-3x)y = e^x - e^(-x)y₁ = e^(-2x), y₂ = xe^(-2x)y₁ = e^x cos(x), y₂ = e^x sin(x)y₁ = cos(x) - cos(2x), y₂ = sin(x) - cos(2x)y = 1 + x²y₁ = x - ln(x), y₂ = -1 - ln(x)y₁ = x², y₂ = x^(-2)y₁ = xcos(ln(x)), y₂ = xsin(ln(x))To verify that each given function is a solution of the given differential equation, we will substitute the function into the differential equation and check if it satisfies the equation.
1. y' = 3x²; y = x³ + 7
Substituting y into the equation:
y' = 3(x³ + 7) = 3x³ + 21
The derivative of y is indeed equal to 3x², so y = x³ + 7 is a solution.
2. y' + 2y = 0; y = 3e^(-2x)
Substituting y into the equation:
y' + 2y = -6e^(-2x) + 2(3e^(-2x)) = -6e^(-2x) + 6e^(-2x) = 0
The equation is satisfied, so y = 3e^(-2x) is a solution.
3. y" + 4y = 0; y₁ = cos(2x), y₂ = sin(2x)
Taking the second derivative of y₁ and substituting into the equation:
y"₁ + 4y₁ = -4cos(2x) + 4cos(2x) = 0
The equation is satisfied for y₁.
Taking the second derivative of y₂ and substituting into the equation:
y"₂ + 4y₂ = -4sin(2x) - 4sin(2x) = -8sin(2x)
The equation is not satisfied for y₂, so y₂ = sin(2x) is not a solution.
4. y" = 9y; y₁ = e^(3x), y₂ = e^(-3x)
Taking the second derivative of y₁ and substituting into the equation:
y"₁ = 9e^(3x)
9e^(3x) = 9e^(3x)
The equation is satisfied for y₁.
Taking the second derivative of y₂ and substituting into the equation:
y"₂ = 9e^(-3x)
9e^(-3x) = 9e^(-3x)
The equation is satisfied for y₂.
5. y' = y + 2e^(-x); y = e^x - e^(-x)
Substituting y into the equation:
y' = e^x - e^(-x) + 2e^(-x) = e^x + e^(-x)
The equation is satisfied, so y = e^x - e^(-x) is a solution.
6. y" + 4y^2 + 4y = 0; y₁ = e^(-2x), y₂ = xe^(-2x)
Taking the second derivative of y₁ and substituting into the equation:
y"₁ + 4(y₁)^2 + 4y₁ = 4e^(-4x) + 4e^(-4x) + 4e^(-2x) = 8e^(-2x) + 4e^(-2x) = 12e^(-2x)
The equation is not satisfied for y₁, so y₁ = e^(-2x) is not a solution.
Taking the second derivative of y₂ and substituting into the equation:
y"₂ + 4(y₂)^2 + 4y₂ = 2e^(-2x) + 4(xe^(-2x))^2 + 4xe^(-2x) = 2e^(-2x) + 4x^2e^(-4x) + 4xe^(-2x)
The equation is not satisfied for y₂, so y₂ = xe^(-2x) is not a solution.
7. y" - 2y + 2y = 0; y₁ = e^x cos(x), y₂ = e^x sin(x)
Taking the second derivative of y₁ and substituting into the equation:
y"₁ - 2(y₁) + 2y₁ = e^x(-cos(x) - 2cos(x) + 2cos(x)) = 0
The equation is satisfied for y₁.
Taking the second derivative of y₂ and substituting into the equation:
y"₂ - 2(y₂) + 2y₂ = e^x(-sin(x) - 2sin(x) + 2sin(x)) = 0
The equation is satisfied for y₂.
8. y" + y = 3cos(2x); y₁ = cos(x) - cos(2x), y₂ = sin(x) - cos(2x)
Taking the second derivative of y₁ and substituting into the equation:
y"₁ + y₁ = -cos(x) + 2cos(2x) + cos(x) - cos(2x) = cos(x)
The equation is not satisfied for y₁, so y₁ = cos(x) - cos(2x) is not a solution.
Taking the second derivative of y₂ and substituting into the equation:
y"₂ + y₂ = -sin(x) + 2sin(2x) + sin(x) - cos(2x) = sin(x) + 2sin(2x) - cos(2x)
The equation is not satisfied for y₂, so y₂ = sin(x) - cos(2x) is not a solution.
9. y' + 2xy² = 0; y = 1 + x²
Substituting y into the equation:
y' + 2x(1 + x²) = 2x³ + 2x = 2x(x² + 1)
The equation is satisfied, so y = 1 + x² is a solution.
10 x²y" + xy' - y = ln(x); y₁ = x - ln(x), y₂ = -1 - ln(x)
Taking the second derivative of y₁ and substituting into the equation:
x²y"₁ + xy'₁ - y₁ = x²(0) + x(1) - (x - ln(x)) = x
The equation is satisfied for y₁.
Taking the second derivative of y₂ and substituting into the equation:
x²y"₂ + xy'₂ - y₂ = x²(0) + x(-1/x) - (-1 - ln(x)) = 1 + ln(x)
The equation is not satisfied for y₂, so y₂ = -1 - ln(x) is not a solution.
11. x²y" + 5xy' + 4y = 0; y₁ = x², y₂ = x^(-2)
Taking the second derivative of y₁ and substituting into the equation:
x²y"₁ + 5xy'₁ + 4y₁ = x²(0) + 5x(2x) + 4x² = 14x³
The equation is not satisfied for y₁, so y₁ = x² is not a solution.
Taking the second derivative of y₂ and substituting into the equation:
x²y"₂ + 5xy'₂ + 4y₂ = x²(4/x²) + 5x(-2/x³) + 4(x^(-2)) = 4 + (-10/x) + 4(x^(-2))
The equation is not satisfied for y₂, so y₂ = x^(-2) is not a solution.
12. x²y" - xy' + 2y = 0; y₁ = xcos(ln(x)), y₂ = xsin(ln(x))
Taking the second derivative of y₁ and substituting into the equation:
x²y"₁ - xy'₁ + 2y₁ = x²(0) - x(-sin(ln(x))/x) + 2xcos(ln(x)) = x(sin(ln(x)) + 2cos(ln(x)))
The equation is satisfied for y₁.
Taking the second derivative of y₂ and substituting into the equation:
x²y"₂ - xy'₂ + 2y₂ = x²(0) - x(cos(ln(x))/x) + 2xsin(ln(x)) = x(sin(ln(x)) + 2cos(ln(x)))
The equation is satisfied for y₂.
Therefore, the solutions to the given differential equations are:
y = x³ + 7
y = 3e^(-2x)
y₁ = cos(2x)
y₁ = e^(3x), y₂ = e^(-3x)
y = e^x - e^(-x)
y₁ = e^(-2x)
y₁ = e^x cos(x), y₂ = e^x sin(x)
y = 1 + x²
y₁ = xcos(ln(x)), y₂ = xsin(ln(x))
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If y varies inversely as the square of x, and y=7/4 when x=1 find y when x=3
To find the value of k, we can substitute the given values of y and x into the equation.
If y varies inversely as the square of x, we can express this relationship using the equation y = k/x^2, where k is the constant of variation.
When x = 1, y = 7/4. Substituting these values into the equation, we get:
7/4 = k/1^2
7/4 = k
Now that we have determined the value of k, we can use it to find y when x = 3. Substituting x = 3 and k = 7/4 into the equation, we get:
y = (7/4)/(3^2)
y = (7/4)/9
y = 7/4 * 1/9
y = 7/36
Therefore, when x = 3, y is equal to 7/36. The relationship between x and y is inversely proportional to the square of x, and as x increases, y decreases.
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how to change a negative exponent to a positive exponent
Recently, a certain bank offered a 10-year CD that earns 2.83% compounded continuously. Use the given information to answer the questions. (a) If $30,000 is invested in this CD, how much will it be worth in 10 years? approximately $ (Round to the nearest cent.) (b) How long will it take for the account to be worth $75,000? approximately years (Round to two decimal places as needed.)
If $30,000 is invested in a CD that earns 2.83% compounded continuously, it will be worth approximately $43,353.44 in 10 years. It will take approximately 17.63 years for the account to reach $75,000.
To solve this problem, we can use the formula for compound interest:
```
A = P * e^rt
```
where:
* A is the future value of the investment
* P is the principal amount invested
* r is the interest rate
* t is the number of years
In this case, we have:
* P = $30,000
* r = 0.0283
* t = 10 years
Substituting these values into the formula, we get:
```
A = 30000 * e^(0.0283 * 10)
```
```
A = $43,353.44
```
This means that if $30,000 is invested in a CD that earns 2.83% compounded continuously, it will be worth approximately $43,353.44 in 10 years.
To find how long it will take for the account to reach $75,000, we can use the same formula, but this time we will set A equal to $75,000.
```
75000 = 30000 * e^(0.0283 * t)
```
```
2.5 = e^(0.0283 * t)
```
```
ln(2.5) = 0.0283 * t
```
```
t = ln(2.5) / 0.0283
```
```
t = 17.63 years
```
This means that it will take approximately 17.63 years for the account to reach $75,000.
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Find all lattice points of f(x)=log3(x+1)−9
Answer:
Step-by-step explanation:
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point ;)
