• 2xy + x ² y' = 0
This DE is exact, since
∂(2xy)/∂y = 2x
∂(x ²)/∂x = 2x
are the same. Then there is a solution of the form f(x, y) = C such that
∂f/∂x = 2xy ==> f(x, y) = x ² y + g(y)
∂f/∂y = x ² = x ² + dg/dy ==> dg/dy = 0 ==> g(y) = C
==> f(x, y) = x ² y = C
• sin(x) cos(y) + cos(x) sin(y) y' = 0
is also exact because
∂(sin(x) cos(y))/∂y = -sin(x) sin(y)
∂(cos(x) sin(y))/∂x = -sin(x) sin(y)
Then
∂f/∂x = sin(x) cos(y) ==> f(x, y) = -cos(x) cos(y) + g(y)
∂f/∂y = cos(x) sin(y) = cos(x) sin(y) + dg/dy ==> dg/dy = 0 ==> g(y) = C
==> f(x, y) = -cos(x) cos(y) = C
• x ² + y ² - 2xyy' = 0
is not exact:
∂(x ² + y ²)/∂x = 2x
∂(-2xy)/∂y = -2x
So we look for an integrating factor µ(x, y) such that
µ (x ² + y ²) - 2µxyy' = 0
becomes exact, which would require that these be equal:
∂(µ (x ² + y ²))/∂y = (x ² + y ²) ∂µ/∂y + 2µy
∂(-2µxy)/∂x = -2xy ∂µ/∂x - 2µy
Observe that if µ(x, y) = µ(x), then ∂µ/∂y = 0 and ∂µ/∂x = dµ/dx, so we would have
2µy = -2xy dµ/dx - 2µy
==> -2xy dµ/dx = 4µy
==> dµ/µ = -2/x dx
Integrating both sides gives
∫ dµ/µ = ∫ -2/x dx ==> ln|µ| = -2 ln|x| ==> µ = 1/x ²
So in the modified DE, we have
(1 + y ²/x ²) - 2y/x y' = 0
which is now exact and ready to solve, since
∂(1 + y ²/x ²)/∂y = 2y/x ²
∂(-2y/x)/∂x = 2y/x ²
We get
∂f/∂x = 1 + y ²/x ² ==> f(x, y) = x - y ²/x + g(y)
∂f/∂y = -2y/x = -2y/x + dg/dy ==> dg/dy = 0 ==> g(y) = C
==> f(x, y) = x - y ²/x = C
• exp(2x) (2 cos(y) - sin(y) y' ) = 0
is exact, since
∂(2 exp(2x) cos(y))/∂y = -2 exp(2x) sin(y)
∂(-exp(2x) sin(y))/∂x = -2 exp(2x) sin(y)
Then
∂f/∂x = 2 exp(2x) cos(y) ==> f(x, y) = exp(2x) cos(y) + g(y)
∂f/∂y = -exp(2x) sin(y) = -exp(2x) sin(y) + dg/dy ==> dg/dy = 0 ==> g(y) = C
==> f(x, y) = exp(2x) cos(y) = C
Given that y = 0 when x = 0, we find that
C = exp(0) cos(0) = 1
so that the particular solution is
exp(2x) cos(y) = 1
What is the value of the expression i 0 × i 1 × i 2 × i 3 × i 4?
1
–1
i
–i
Answer:
Answer is -1
Step-by-step explanation:
i1 = i
i2 = -1
i3 = -i
i4 = 1
i0 × i1 × i2 × i3 × i4 = 1 × i × (- 1) × (- i) × 1 = i2 = - 1
Answer:the answer is -1
Step-by-step explanation:
If 1 kilogram (kg) is equal to about 2.2046 pounds (lbs.), what is the value of 1kg/2.2046lbs? What is the value of 2.2046lbs/1kg?
Step-by-step explanation:
The relation between kg and lbs is :
1 kg = 2.2046 lbs
We need to find the values of 1kg/2.2046lbs and 2.2046lbs/1kg.
So,
[tex]\dfrac{1\ kg}{2.2046\ lbs}=\dfrac{2.2046\ lbs}{2.2046\ lbs}\\\\=1[/tex]
and
[tex]\dfrac{2.2046\ lbs}{1\ kg}=\dfrac{2.2046\ lbs}{2.2046\ lbs}\\\\=1[/tex]
Hence, this is the required solution.
Answer:
Both are same as 1.
Step-by-step explanation:
1 kg = 2.2046 lbs
So,
[tex]\frac{1 kg}{2.2046 lbs }=\frac{1 kg }{1 kg} = 1[/tex]
And
[tex]\frac{2.2046 lbs}{1 kg }=\frac{1 kg }{1 kg} = 1[/tex]
Norman and Suzanne own 35 shares of a fast food restaurant stock and 63 shares of a toy company stock. At the close of the markets on a particular day in 2004, their stock portfolio consisting of these two stocks was worth $1596.00. The closing price of the fast food restaurant stock was $19 more per share than the closing price of the toy company stock on that day. What was the closing price of each stock on that day? The price per share of the fast food restaurant stock is
Answer:
closing price of the fast food stock was $997.50
closing price of the toy company stock was $598.50
the price per fast food share was $28.50
Step-by-step explanation:
x = price per share fast food
y = price per share toy company
35x + 63y = 1596
x = y + 19
=>
35(y+19) + 63y = 1596
35y + 665 + 63y = 1596
98y + 665 = 1596
98y = 931
y = $9.50
=>
x = 9.5 + 19 = $28.50
the value of the whole fast food stock was
35x = 35×28.5 = $997.50
the cake if the whole toy company stock was
63y = 63×9.5 = $598.50
A formula for the normal systolic blood pressure for a man age A, measured in mmHg, is given as P = 0.006A*2-0.02A + 120. Find the age of a man whose normal blood pressure measures 129 mmHg. Round your answer to the nearest year. The man would be ? years old.
Answer:
The man would be 40 years old.
Step-by-step explanation:
Blood pressure as function of age:
Is given by the following equation:
[tex]P = 0.006A^2 - 0.02A + 120[/tex]
Find the age of a man whose normal blood pressure measures 129 mmHg.
This is A for which P = 129. So
[tex]129 = 0.006A^2 - 0.02A + 120[/tex]
[tex]0.006A^2 - 0.02A - 9 = 0[/tex]
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
[tex]ax^{2} + bx + c, a\neq0[/tex].
This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:
[tex]x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}[/tex]
[tex]x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}[/tex]
[tex]\Delta = b^{2} - 4ac[/tex]
In this question:
Quadratic equation with [tex]a = 0.006, b = -0.02, C = -9[/tex]. So
[tex]\Delta = (-0.02)^2 - 4(0.006)(-9) = 0.2164[/tex]
[tex]A_{1} = \frac{-(-0.02) + \sqrt{0.2164}}{2*(0.006)} = 40.4[/tex]
[tex]A_{2} = \frac{-(-0.02) - \sqrt{0.2164}}{2*(0.006)} = -37.1[/tex]
Age has to be a positive number, so rounding to the nearest year:
The man would be 40 years old.
A certain brand of coffee comes in two sizes. An 11.5-ounce package costs $.4.24 . A 27.8-ounce package costs $9.98.
Find the unit price for each size. Then state which size is the better buy based on the unit price.
Round your answers to the nearest cent.
Answer:
Small (11.5) is 37 cents per ounce.
Large (27.8) is 36 cents per ounce.
27.8 ounces is the better buy.
The triangles below are similar (being similar means there is a proportional relationship between the measures of each of the sides). What is the length of ED? (HINT: You can solve this question by using the MATH Ratio Table)
=================================================
Work Shown:
ED/DF = AB/AC
x/24 = 12/16
16x = 24*12
16x = 288
x = 288/16
x = 18
------------
Explanation:
Because the triangles are similar, we can form the proportion shown above. There are many variations of the proportion that can happen, but they all lead to the same result x = 18.
So for instance, another proportion you could solve is ED/AB = DF/AC.
The key is to keep up the same pattern when forming the ratios.
What I mean by that is when I formed ED/DF I divided the vertical side over the horizontal side for triangle EDF. So to form the second fraction, we must do the same division (vertical over horizontal) for triangle ABC.
A train is traveling at a speed of 60 miles per hour. What happens to the number of miles when the number of hours
changes?
Abebe babe
Answer:
It multiplies
Step-by-step explanation:
if the number of hours changes to example to 2 then you multiply 60 by 2 resulting in 120miles in 2 hours
The theoretical mean of a distribution is also known as its ______________.
Answer:
skewness
Step-by-step explanation:
Average.
The average of a set of observations is the most important and useful measure of statistics and is a position measure, as it shows the positions of the numbers to which it refers. The average value is involved in several types of statistics and is examined in almost all statistical distributions. It is generally defined as the sum of the observations by their number. That is, it is the mathematical operation of finding the "mean distance" between two or more numbers.
Learn more about averages in https://brainly.com/question/22390452
If there is a die that has 12 sides, that are numbered 1 to 12, what is the probability that she will roll either a 3 or a 9
Answer:
2/12 = 1/6
Step-by-step explanation:
To find the probability of something with an equal chance of each outcome, we can apply the formula (number of favorable outcomes)/(number of total outcomes). Because there is an equal chance for each side of the die to be landed on, we can apply this.
On a 12 sided die, there are 12 sides. Two of those sides are 3 and 9. Therefore, there are two favorable outcomes (3 and 9). There are 12 sides to choose from, so there are 12 total outcomes, making the probability 2/12 = 1/6
Simplify 7a – 11b + 4ab – 6a + 5b.
There are three separate, equal-size boxes, and inside each box there are four separate small boxes, and inside each of the small boxes there are three even smaller boxes. how many boxes are there all together?
Answer:
There are 51 boxes all together.
Step-by-step explanation:
Since there are three separate, equal-size boxes, and inside each box there are four separate small boxes, and inside each of the small boxes there are three even smaller boxes, to determine how many boxes are there all together, the following calculation must be done:
3 + 3 x 4 + 3 x 4 x 3 = X
3 + 12 + 36 = X
51 = X
Therefore, there are 51 boxes all together.
Using the Time Series Data for the US Nuclear Electric Power Production, calculate the exponential smoothing forecasts for 2005 through 2010 using alpha equals 0.2. Find the forecast error for each time period. If there is n
Answer:
????????????
I don't know
Perimeter (numerical)
Answer:
270 m
Step-by-step explanation:
Add up all the sides
P = 19 +18.8+18.8 +18.8+18.8+40.8+19+40.8+18.8+18.8+18.8+18.8
P = 270 m
Do number 7 plz finding QR
Answer:
QR = sqrt(147)
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 + b^2 = c^2
7^2 + QR^2 = 14^2
49 + QR^2 = 196
QR^2 = 196-49
QR^2 = 147
Taking the square root of each side
QR = sqrt(147)
find the constant of variation k for the direct variation. 4x = -y
Answer:
k = - 4
Step-by-step explanation:
The equation representing direct variation is
y = kx ← k is the constant of variation
Given
4x = - y ( multiply both sides by - 1 )
- 4x = y , that is
y = - 4x ← in standard form
with k = - 4
I need help with this
Answer:
D.
Step-by-step explanation:
According to converse of the Pythagorean Theorem, that if the square of the third side (longest side) of a triangle equals the sum of the other two shorter sides, therefore, the triangle formed must be a right triangle.
From the side lengths given, the following satisfies the Pythagorean triple:
5² + 12² = 13².
Therefore, the procedure to use to confirm the converse of the Pythagorean Theorem would be to draw the two shortest side, 5 cm and 12 cm, so that a right angle will be between them. The side measuring 13 cm should therefore fit in to form a right triangle.
construct an angle that bisect 120°
Answer:
just make a 120 angle and divide it by 2, 60.
Which graph represents y = |xl?
A
B
C
D
Answer:
B
Step-by-step explanation:
The equation represented in the question is the parent absolute value question. If you know the different parent functions, then the answer is obvious because absolute value equations always form a V. However, if you do not do this then you can create a table and plugin values. Plugin numbers like 0, -1, and 1 for X and solve for Y. Finally, graph these points and see what graph best fits. If needed you can also plug in more points.
Answer:
B.
Step-by-step explanation:
I got it correct on the warm up
The director of special events for Sun City believed that the amount of money spent on fireworks displays on the 4th of July was predictive of attendance at the Fall Festival held in October. She gathered the following data to test her suspicion.
4th of July ($000) Fall Festival (000)
10.6 8.8
8.5 6.4
12.5 10.8
9.0 10.2
5.5 6.0
12 11.1
8.0 7.5
7.5 8.4
9.0 9.5
10 9.8
7.5 6.6
10 10.1
6.0 6.1
12 11.3
10.5 8.8
Required:
Determine the regression equation. Is the amount spent on fireworks related to attendance at the Fall Festival? Conduct a hypothesis test to determine if there is a problem with autocorrelation.
Answer:
The complete question and its solution in the attached file please find it.
Step-by-step explanation:
Solve this equation for x. Round your answer to the nearest hundredth. 0.77 = log x
Answer:
x ≈ 5.89
General Formulas and Concepts:
Pre-Algebra
Equality PropertiesAlgebra II
Exponential to Logarithmic: [tex]\displaystyle b^m=x \rightarrow log_bx=m[/tex]Step-by-step explanation:
Step 1: Define
Identify
0.77 = log(x)
Step 2: Solve for x
[Equality Property] Raise both sides to the 10th power: [tex]\displaysytle 10^{0.77} = 10^{logx}[/tex]Simplify: [tex]\displaysytle x = 10^{0.77}[/tex]Evaluate: [tex]\displaysytle x = 5.88844[/tex]Nadia needs 3/4 cup of orange juice for a punch recipe. She will double the recipe to make
punch for a party. Which statement is true?
Answer:
she will be using more orange juice
Answer:
she will be using more orange juice
The value of 33 + 42 = ___.
Numerical Answers Expected!
Answer for Blank 1:
[tex] \sf Q) \: {3}^{3} + {4}^{2} = {?}[/tex]
[tex] \sf \to \: {3}^{3} + {4}^{2} [/tex]
[tex] \sf \to \: 27 + 16= 43 [/tex]
Thus, the value is 43.
20 slips of paper are put into a bag numbered from 1 to 20. One slip is randomly selected from the bag. We are interested in selecting even numbers. What is the probability of selecting an even number from the bag?
Answer:
2/5
Step-by-step explanation:
Answer:
Step-by-step explanation:
There are 10 even numbers from 1 to 20
2 4 6 8 10 12 14 16 18 20
There 20 possible choices.
P(Even) = 10 /20 = 1/2
A trough has ends shaped like isosceles triangles, with width 2 m and height 5 m, and the trough is 18 m long. Water is being pumped into the trough at a rate of 8 m3/min. At what rate (in m/min) does the height of the water change when the water is 2 m deep
9514 1404 393
Answer:
5/9 m/min
Step-by-step explanation:
The depth of the water is 2/5 of the depth of the trough, so the width of the surface will be 2/5 of the width of the trough:
2/5 × 2 m = 4/5 m
Then the surface area of the water is ...
A = LW = (18 m)(4/5 m) = 14.4 m²
The rate of change of height multiplied by the area gives the rate of change of volume:
8 m³/min = (14.4 m²)(h')
h' = (8 m³/min)/(14.4 m²) = 5/9 m/min
Find the slope of the line #67
The wholesale price of 6 oz plastic bottles is 6 cents how many plastic bottles can be purchased for $98.41
Answer:
1640
Step-by-step explanation:
Take the total amount and divide by the amount for one
Make sure to write 6 cent in dollar form (.06)
98.41 / .06
1640.1666
Round down since we need to buy whole bottles
1640
Find the medien: 16,12,10,15,7,9,16
Answer:
12
Step-by-step explanation:
arrange the numbers in ascending order and cross out from either side till you have a middle line
FINAL ANSWER:
12
Step-by-step explanation:
Median is the middle number in the data set.
so first of ... we need to arrange the group of numbers from lower to greater.
16, 12, 10, 15, 7, 9, 16 ⇒ 7, 9, 10, 12, 15, 16, 16
Now that we have arranged the numbers from least to greatest all we need to do is to find the middle number of the data set (data set? they are the group of numbers)
Ok, so what you want to do here is to just count the numbers until you get to the middle number of the data set...
7, 9, 10, 12, 15, 16, 16
the median in the given data set is 12.
I hope this helps you!!! Let me know if my answer is incorrect or not...
HAVE A GREAT DAY AND GOD BLESS YOU ;)!!!
Britany wants to read a book. In her room, she has 5 mysteries, 15 historical fictions, 12 modern fantasies, and 7 blographies.
How many different choices are available?
pleaseee
Answer:
39
Step-by-step explanation:
5 + 15 + 12 + 7 = 39
Answer:
39
Step-by-step explanation:
5 + 15 = 20, 12 + 7 = 19, 20 + 19 = 39.
Simplify: 3.5 x 10^-2 + 2.3 x 10^-2
Given:
The given expression is:
[tex]3.5\times 10^{-2}+2.3\times 10^{-2}[/tex]
To find:
The simplified form of the given expression.
Solution:
We have,
[tex]3.5\times 10^{-2}+2.3\times 10^{-2}[/tex]
It can be written as:
[tex]=(3.5+2.3)\times 10^{-2}[/tex]
[tex]=5.8\times 10^{-2}[/tex]
Therefore, the simplified form of the given expression is [tex]5.8\times 10^{-2}[/tex].
Michael drove 210 miles in 3 1/2. Jordan drove 330 miles in 6 hours. Which is an accurate comparison of the rates at which the two people drove?
Michael = 210 / 3.5 = 60 miles per hour
Jordan = 330/ 6 =55 miles per hour
Jordan drove 5 miles per hour slower than michael
