Answer:
a. the control limits should be set at (10.72, 11.28)
b. [tex]\mathbf{P(10.72<x<11.28) = 0.4526}[/tex]
c. [tex]\mathbf{P(10.72<x<11.28) = 0.0065}[/tex]
Step-by-step explanation:
Given that:
population mean μ = 11
standard deviation [tex]\sigma[/tex] = 1.0
sample size n = 35
5% of the sample means will be greater than the upper control limit, and 5% of the sample means will be less than the lower control limit.
Therefore, level of significance ∝ = 0.05+0.05 = 0.10
Critical value for [tex]z_{1-\alpha/2} =z_{1-0.10 /2}[/tex]
[tex]\implies z_{1-0.05} = z_{0.95}[/tex]
Using the EXCEL FORMULA: = NORMSINV (0.95)
z = 1.64
The lower control limit and the upper control limit can be determined by using the respective formulas:
Lower control limit = [tex]\mathtt{\mu - z_{1-\alpha/2} \times \dfrac{\sigma}{\sqrt{n}}}[/tex]
Upper control limit = [tex]\mathtt{\mu + z_{1-\alpha/2} \times \dfrac{\sigma}{\sqrt{n}}}[/tex]
For the lower control limit = [tex]11-1.64 \times \dfrac{1.0}{\sqrt{35}}[/tex]
For the lower control limit = [tex]11-0.27721[/tex]
For the lower control limit = 10.72279
For the lower control limit [tex]\simeq[/tex] 10.72
For the upper control limit = [tex]11+1.64 \times \dfrac{1.0}{\sqrt{35}}[/tex]
For the upper control limit = 11 + 0.27721
For the upper control limit = 11.27721
For the upper control limit [tex]\simeq[/tex] 11.28
Therefore , the control limits should be set at (10.72, 11.28)
b. If the population mean shifts to 10.7, what is the probability that the change will be detected?
i.e
[tex]\mathtt{P(10.72<x<11.28) = P( \dfrac{X- \mu}{\dfrac{\sigma}{\sqrt{n}}}<z < \dfrac{X- \mu}{\dfrac{\sigma}{\sqrt{n}}}})[/tex]
[tex]\mathtt{P(10.72<x<11.28) = P( \dfrac{10.72- 10.7}{\dfrac{1.0}{\sqrt{35}}}<z < \dfrac{11.28- 10.7}{\dfrac{1.0}{\sqrt{35}}}})[/tex]
[tex]\mathtt{P(10.72<x<11.28) = P( \dfrac{0.02}{\dfrac{1.0}{5.916}}<z < \dfrac{0.58}{\dfrac{1.0}{5.916}}})[/tex]
[tex]\mathtt{P(10.72<x<11.28) = P(0.1183<z < 3.4313})[/tex]
[tex]\mathtt{P(10.72<x<11.28) = P(z< 3.4313) - P(z< 0.1183) }[/tex]
Using the EXCEL FORMULA: = NORMSDIST (3.4313) - NORMSDIST (0.118 ); we have:
[tex]\mathbf{P(10.72<x<11.28) = 0.4526}[/tex]
c If the population mean shifts to 11.7, what is the probability that the change will be detected?
i.e
[tex]\mathtt{P(10.72<x<11.28) = P( \dfrac{X- \mu}{\dfrac{\sigma}{\sqrt{n}}}<z < \dfrac{X- \mu}{\dfrac{\sigma}{\sqrt{n}}}})[/tex]
[tex]\mathtt{P(10.72<x<11.28) = P( \dfrac{10.72- 11.7}{\dfrac{1.0}{\sqrt{35}}}<z < \dfrac{11.28- 11.7}{\dfrac{1.0}{\sqrt{35}}}})[/tex]
[tex]\mathtt{P(10.72<x<11.28) = P( \dfrac{-0.98}{\dfrac{1.0}{5.916}}<z < \dfrac{-0.42}{\dfrac{1.0}{5.916}}})[/tex]
[tex]\mathtt{P(10.72<x<11.28) = P(-5.7978<z < -2.48472})[/tex]
[tex]\mathtt{P(10.72<x<11.28) = P(z< -2.48472) - P(z< -5.7978) }[/tex]
Using the EXCEL FORMULA: = NORMSDIST (-2.48472) - NORMSDIST (-5.7978); we have:
[tex]\mathbf{P(10.72<x<11.28) = 0.0065}[/tex]
are:
4. Suppose that the distance of fly balls hit to the outfield (in baseball) is normally
distributed. We randomly sample 27 fly balls. Their recorded distances in feet
234, 310, 285, 249, 210, 311, 265, 290, 308,
254, 295, 287, 231, 302, 325, 308, 221, 237,
312, 277, 259, 223, 340, 204, 214, 303, 309
Let X be the distance of a fly ball.
Use Excel to calculate the following:
a. (1 pt) mean of the sample, x =
b. (1 pt) standard deviation of the sample, s =
C. (2 pts) Calculate the t-score at a 96% confidence level:
d. (2 pts) Calculate the Error Bound (EBM), using the formula, EBM =
(t)(s//n)
e. (1 pt) At 96% confidence level, provide the confidence interval (CI) for the
mean distance in feet of a fly ball.
hantor 92
D
Step-by-step explanation:
a. The mean can be found using the AVERAGE() function.
x = 272.7
b. The standard deviation can be found with the STDEV() function.
s = 39.9
c. The t-score can be found with the T.INV.2T() function. The confidence level is 0.04, and the degrees of freedom is 26.
t = 2.162
d. Find the lower and upper ends of the confidence interval.
Lower = 272.7 − 2.162 × 39.9 = 186.5
Upper = 272.7 + 2.162 × 39.9 = 358.9
I have no idea what to do here.
Answer:
15.5846.>
Step-by-step explanation:
Please help! I’ll mark you as brainliest if correct.
Answer:
160 liters of 25%, 20 liters of 40%, 60 liters of 60%
Step-by-step explanation:
x + y + z = 240
0.25x + 0.4y + 0.6z = 0.35*240 = 84
z = 3y
x = 160
y = 20
z = 60
Consider the age distribution in the United States in the year 2075 (as projected by the Census Bureau). Construct a cumulative frequency plot and describe what information the plot communicates about the distribution of ages in the future.
Answer:
The cumulative frequency plot is also attached below.
Step-by-step explanation:
The data provided is as follows:
Age Group Frequency
0 - 9 34.9
10 - 19 35.7
20 - 29 36.8
30 - 39 38.1
40 - 49 37.8
50 - 59 37.8
60 - 69 34.5
70 - 79 27.2
80 - 89 18.8
90 - 99 7.7
100 - 109 1.7
Consider the Excel output attached.
The cumulative frequency are computed in the Excel sheet.
The cumulative frequency plot is also attached below.
From the cumulative frequency plot it can be seen that in the future most people will belong to a higher age group rather then the lower ones.
Evaluate
1+5.3
2
please answer quickly
Answer:
1+5.3=6.3
Step-by-step explanation:
not sure what your asking for with the 2
explain what your looking for with the 2 and maybe we can help you further
(I have to do it the way I did it because the 2 in the question is confusing)
Answer:
For expression 1 + 5.32: 6.32
For expression 1 + 5.3 × 2: 11.6
Step-by-step explanation:
If the expression is 1 + 5.32:
Add 1 to 5.32: 1 + 5.32 = 6.32If the expression is 1 + 5.3 × 2:
5.3 × 2 = 10.6Plug in 10.6: 1 + 10.61 + 10.6 = 11.6
F
19) The points (6,5), (7,2), (9,6), and (10,3) are vertices of an inscribed square.
A)(x - 8)2-(y - 4)2 = 5
B) (x – 8)2 + (y - 4)2 = 15
C) (X + 8)2 + (y + 4)2 = 5
D) (x - 8)2 + (y - 4)2 = 5
Find an equation for the circle
Answer:
The equation of circle is [tex](x-8)^2+(y-4)^2=5[/tex]
(D) is correct option.
Step-by-step explanation:
Given that,
Points (6,5), (7,2), (9,6) and (10,3) are vertices of an inscribed square.
We need to calculate the distance between (7,2) and (9,6)
Using formula of distance
[tex]d=\sqrt{(x_{2}-x_{1})^2+(y_{2}-y_{1})^2}[/tex]
Put the value into the formula
[tex]d^2=(9-7)^2+(6-2)^2[/tex]
[tex]d^2=20\ m[/tex]
The radius will be
[tex]r^2=\dfrac{20}{4}[/tex]
[tex]r^2=5[/tex]
We need to calculate the center of the point (7,2) and (9,6)
Using formula of center point
For x axis,
[tex]h=\dfrac{x_{2}+x_{1}}{2}[/tex]
Put the value into the formula
[tex]h=\dfrac{9+7}{2}[/tex]
[tex]h=\dfrac{16}{2}[/tex]
[tex]h=8[/tex]
For y axis,
[tex]k=\dfrac{y_{2}+y_{1}}{2}[/tex]
Put the value into the formula
[tex]k=\dfrac{6+2}{2}[/tex]
[tex]k=\dfrac{8}{2}[/tex]
[tex]k=4[/tex]
We need to find the equation for the circle
Using formula of equation of circle
[tex](x-h)^2+(y-k)^2=r^2[/tex]
Put the value into the formula
[tex](x-8)^2+(y-4)^2=5[/tex]
Hence, The equation of circle is [tex](x-8)^2+(y-4)^2=5[/tex]
(D) is correct option.
Show all work to solve 3x2 − x − 2 = 0.
Answer:
x=-2/3 and 1
Step-by-step explanation:
3x^2-x-2=0
(3x+2)(x-1)
3x=-2
x=-2/3
x=1
Anand needs to hire a plumber. He's considering a plumber that charges an initia
hourly rate of $28. The plumber only charges for a whole number of hours. Anar
more than $250, and he wonders how many hours of work he can afford.
Let H represent the whole number of hours that the plumber works.
1) Which inequality describes this scenario?
Choose 1 answer:
28 - 65H <250
Complete question :
Anand needs to hire a plumber. He's considering a plumber that charges an initial fee of $65 along with an
hourly rate of $28. The plumber only charges for a whole number of hours. Anand would like to spend no more than $250, and he wonders how many hours of work he can afford.
Let H represent the whole number of hours that the plumber works.
1) Which inequality describes this scenario?
Choose 1 answer:
A. 28 + 65H < 250
B. 28 + 65H > 250
C. 65 + 28H < 250
D. 65 +28H > 250
2) What is the largest whole number of hours that Anand can afford?
Answer:
65 + 28H < 250
Number of hours Anand can afford = 6 hours
Step-by-step explanation:
Given the following information :
Initial hourly rate = $65
Hourly rate = $28
Number of hours worked (whole number) = H
Maximum budgeted amount to spend = $250
Therefore ;
(Initial charge + total charge in hours) should not be more than $250
$65 + ($28*H) < $250
65 + 28H < 250
Number of hours Anand can afford :
65 + 28H < 250
28H < 250 - 65
28H < 185
H < (185 / 28)
H < 6.61
Sinve H is a whole number, the number of hours he can afford is 6 hours
Answer:
65 + 28H < 250
6
Step-by-step explanation:
tried it, it worked.
the other answer is correct but hard to understand so give them thanks and 4 star :)
Laura is bowling 5 games. Her first 4 scores were 135, 144, 116, and 132.
To end up with an average score of at least 136.8, what is the lowest score Laura will need in the fifth game?
Answer:
157
Step-by-step explanation:
135+144+116+132=527
527+136.8=762.8
762.8÷5= 157
6. If the equations kx - y = 2 and 6x - 2y = 3 have a solution then state the value of k a) K = 3 b) k 3 c ) K 0 d) k = 0 7.
Answer:
k ≠ 3Step-by-step explanation:
Given the system of equation;
kx - y = 2 ------------------- 1
6x - 2y = 3 -------------------- 2
Rewriting the equations in the format ax+by+c = 0
Equation 1 becomes kx - y - 2 = 0
Equation 2 becomes 6x - 2y - 3 = 0
where a₁ = k, b₁ = -1 and c₁ = -2 and a₂ = 6, b₂ = -2 and c₂ = -3
For the system of equation to have a unique solution the following must be true;
a₁/a₂ ≠ b₁/b₁
Substituting the coefficients into the condition, we will have;
k/6 ≠ -1/-2
k/6 ≠ 1/2
Cross multiplying we will have;
2k ≠ 6
k ≠ 6/2
k ≠ 3
This means that k can be any other real values except 3 for the system of equation to have a unique solution.
in the diagram, POS and UOR are straight lines. OQ is the bisector of angle POR . angle POU and angle UOT are complementary angles.Find the values ofx abd y.
Answer:
x = 34° and y = 62°
Step-by-step explanation:
Complementary angles sum to 90°, therefore 90 = 56 + x which means that x = 34°. The angles formed by an angle bisector are congruent and so are vertical angles; this means that ∠SOR = ∠POU = 56° and ∠POQ = ∠QOR = y. Since POS is a straight line, straight lines have a measure of 180° and because ∠POS = ∠POQ + ∠QOR + ∠SOR, we know that 180 = y + y + 56 → 180 = 2y + 56 → 180 → 2y = 124 → y = 62°.
Olcquations
Week 5 Assignment: Mixture Problems and Systems of Equations
Due Sunday by 11:59pm
Points 10
Submitting an external tool
Solve interest applications using a system of equations
Question
Matthew invested $3,000 into two accounts. One account paid 3% interest and the other paid 8% interest. He earned 4%
interest on the total investment. How much money did he put in each account?
Sorry, that's incorrect. Try again?
3% amount: S 600
8% amount: S 2400
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Answer:
$600 at 8%$2400 at 3%Step-by-step explanation:
You have the right numbers, but the wrong accounts.
__
Let x represent the amount invested at 8% (the highest rate). Then the total interest is ...
.08x +.03(3000 -x) = .04(3000)
.05x = .01(3000) . . . . subtract .03(3000)
x = 3000/5 = 600
Matthew invested $600 at 8%, $2400 at 3%.
_____
Comment on checking your answer
You may notice that the overall interest rate is 4%, closer to 3% than to 8%. That means more of the money must be invested at 3% than at 8%.
What is the area of polygon XYZ?
Answer:
B. 36 square units
Step-by-step explanation:
This is a triangle and to calculate the area of a triangle we multiply height with base and that divided by two
The height of this triangle is 8 units and the base is 9 units
9 × 8 ÷ 2 = 36 square units
Evaluate the expresión 6c-d when c=2 and d=10 I need help?
Answer:
the answer is 18
Step-by-step explanation:
8 is the answer
How do you evaluate this?
[tex]_6C_3=\dfrac{6!}{3!3!}=\dfrac{4\cdot5\cdot6}{2\cdot3}=20[/tex]
I need help with this!
Answer:
i) [tex]\frac38\pi[/tex]
ii) n = 33
Step-by-step explanation:
For this question you can actually focus on the sine, and forget about the e power. The x-coordinates of the extremes of the curve will be the same as for y=sin(4x)
i) equivalent to solving sin(4x) = -1, so 4x = 3/2 pi, x=3/8 pi
ii) The Tn values are at x = (n·π - π/2)/4
solving (n·π - π/2)/4 > 25 gives:
n > 1/2 + 100/π, so n > 32.331, but n must be integer, so we get n=33
In a triangle ABC two points D,E are taken on BC so that angle BAD=angle DAE=angleCAE. Determine AE if AB=5,BC=10 angle BAC=90. PLEASE HELP I NEED HELP WITHIN TEN MINS PLEASE
Answer:
AE = 7.5
Step-by-step explanation:
Since <BAC = [tex]90^{0}[/tex], then;
<BAD = <DAE = <CAE = [tex]30^{0}[/tex] (complementary angles)
From ΔABC, applying the Pythagoras theorem to determine the length of side AC;
[tex]/BC/^{2}[/tex] = [tex]/AC/^{2}[/tex] + [tex]/AB/^{2}[/tex]
[tex]/10/^{2}[/tex] = [tex]/AC/^{2}[/tex] + [tex]/5/^{2}[/tex]
100 = [tex]/AC/^{2}[/tex] + 25
[tex]/AC/^{2}[/tex] = 100 - 25
[tex]/AC/^{2}[/tex] = 75
AC = [tex]\sqrt{75}[/tex]
Applying trigonometric function to ΔCAE,
Cos [tex]30^{0}[/tex] = [tex]\frac{AE}{\sqrt{75} }[/tex]
AE = [tex]\sqrt{75}[/tex] × Cos [tex]30^{0}[/tex]
= 7.5
Therefore, AE = 7.5
Find the degree, leading coefficient, and the constant term of the polynomial.
[tex] \LARGE{ \boxed{ \purple{ \rm{Answers;)}}}}[/tex]
☃️ Degree of the polynomial- The highest degree of any term in a polynomial. Here the highest degree is 5.
⇛ 4x⁴ + 5 + 6x⁵ - 2x(° of polynomial = 5)
☃️ Leading coefficient- The coefficient of the term having the highest degree of the polynomial. Here, the highest degree is 5 and the term is 6x⁵
⇛ 4x⁴ + 5 + 6x⁵ - 2x (Leading coeff. = 6)
☃️ Constant term- It is the term having no coefficients, only a fixed real number. This remains constant in any value of polynomial.
⇛ 4x⁴ + 5 + 6x⁵ - 2x (Constant term = 5)
━━━━━━━━━━━━━━━━━━━━
When determining the sample size necessary for estimating the true population mean, which factor is NOT considered when sampling with replacement
Answer:
Population Size
Step-by-step explanation:
When sampling with replacement, we can expect that the population size will remain the same. Sampling with replacement occurs when a unit or subject for research is chosen from a population at random. This chosen unit can be returned to the population and another random selection done with the possibility that a unit that was chosen before could be chosen again. So in applying this system of selection, the population size is not taken into consideration. When samples are chosen in this form, it can be referred to as a simple random sample.
So, when determining the sample size necessary for estimating the true population mean, using the sampling with replacement method, the population size is not considered.
A signal light is green for 4 minutes, yellow for 10 seconds, and red for 3 minutes. If you drive up to this light, what is the probability that it will be green when you reach the intersection? Round your answer to two decimal places.
Answer:
0.56 is the required probability.
Step-by-step explanation:
Time for which signal shows green light = 4 minutes
Time for which signal shows yellow light = 10 seconds
Time for which signal shows red light = 3 minutes
To find:
Probability that the signal will show green light when you reach the destination = ?
Solution:
First of all, let us convert each time to same unit before doing any calculations.
Time for which signal shows green light = 4 minutes = 4 [tex]\times[/tex] 60 seconds = 240 seconds
Time for which signal shows yellow light = 10 seconds
Time for which signal shows red light = 3 minutes = 3 [tex]\times[/tex] 60 seconds = 180 seconds
Now, let us have a look at the formula for probability of an event E:
[tex]P(E) = \dfrac{\text{Number of favorable cases}}{\text {Total number of cases}}[/tex]
Here, E is the event that green light is shown by the signal.
Number of favorable cases mean the time for which green light is shown and Total number of cases is the total time (Time for which green light is shown + Time for which Yellow light is shown + Time for which red light is shown)
So, the required probability is:
[tex]P(E) = \dfrac{240}{240+10+180}\\\Rightarrow P(E) = \dfrac{240}{430}\\\Rightarrow \bold{P(E) \approx 0.56 }[/tex]
General solution of equation sin x + sin 5x = sin 2x + sin 4x is
Answer:
x=nπ3, n∈I
Step-by-step explanation:
sin x + sin 5x = sin 2x + sin 4x
⇒⇒ 2 sin 3x cos 2x = 2 sin 3x cos x
⇒⇒ 2 sin 3x(cos 2x - cos x) = 0
⇒ sin 3x=0 ⇒ 3x=nπ ⇒ x=nπ3⇒ sin 3x=0 ⇒ 3x=nπ ⇒ x=nπ3 , n∈I, n∈I
or cos 2x−cos x=0 ⇒ cos 2x=cos xcos 2x-cos x=0 ⇒ cos 2x=cos x
⇒ 2x=2nπ±x ⇒ x=2nπ, 2nπ3⇒ 2x=2nπ±x ⇒ x=2nπ, 2nπ3 , n∈I, n∈I
But solutions obtained by x=2nπx=2nπ , n∈I, n∈I or x=2nπ3x=2nπ3 , n∈I, n∈I are all involved in x=nπ3x=nπ3 , n∈I
The Brooklyn Burn is a small company that makes and sells hot sauces. The profit that The
Brooklyn Burn makes in a month from its “Buckingham Burn" hot sauce can be measured using
the following function:
y=6x - 200
where x is the number of bottles of "Buckingham Burn" hot
sauce sold, and y is the profit in dollars for the month.
Using this function and its context involving sales of hot
sauce), describe the meaning of the numbers shown in the
table at the right.
150
700
Answer:
I know the answer
Step-by-step explanation:
If we use 150 the answer would be 6(150) - 200 = 700. The answer is 200.
Brooklyn Burn sold 150 bottles of hot sauce every month, 700 is the profit they make eachmonth.
Please answer this correctly without making mistakes
Answer:
10 9/20
Step-by-step explanation:
Hey there!
If Hillsboro to Campbell is 16 2/20 and Hillsboro to Oxford is 5 13/20,
we’ll do
16 2/20 - 5 13/20
Imrpoper form
322/20 - 113/20
322 - 113
209/20
10 9/20 miles from Oxford to Campbell.
Hope this helps :)
One side of a right triangle is known to be 12 cm long and the opposite angle is measured as 30°, with a possible error of ±1°. Use differentials to estimate the error in computing the length of the hypotenuse. (Round your answer to two decimal places.)
Answer:
estimated error=±0.725
Step-by-step explanation:
Side of the triangle= 12cm
Opposite of triangle x= 30
h= hypotenose side
Error= =±1
From trigonometry
Sin(x)=opposite/hypotenose
hypotenose=opposite/sin(x)
h=12/sin(x)
h=12Csc(x)
dh=-12Csc(x)Cot(x) dx...............eqn(1)
dx is the possible error in angle measurements
So we need to convert to radius
dx=±1°× (π/180)
=±1°(π/180)
Substitute x and dx into equation (1)
dh= - 12Csc30°Cot30°×[±(π/180)]
= -12(2)(√3)(±(π/180)
==±0.725
Therefore, estimated error=±0.725
Calculate the surface area of this composite shape.
Answer:
1284 m^2
Step-by-step explanation:
Front face and back face:
2 * [28 m * 5 m + (22 m - 5 m) * 6 m] = 484 m^2
Left face and right face:
2 * 22 m * 8 m = 352 m^2
Bottom face and top face:
2 * 28 m * 8 m = 448 m^2
total surface area = 484 m^2 + 352 m^2 + 448 m^2 = 1284 m^2
What is the number of square units in the area of the triangle whose vertices are points A(2,0), B(6,0), and C(8,5)?
10 units squared. Hope this helped.
The area of the triangle is 10 square units.
The given coordinates are A(2,0), B(6,0), and C(8,5).
What is the formula to find the area of a triangle?The formula of area of triangle formula in coordinate geometry is the area of the triangle in the coordinate geometry is: [tex]A=\frac{1}{2} |x_{1} (y_{2}-y_{3})+x_{2} (y_{3}-y_{1})+x_{3} (y_{1}-y_{2})|[/tex]
Now, Area=1/2|2(0-5)+6(5-0)+8(0-0)|=0.5|20|
=10 square units
Therefore, the area of the triangle is 10 square units.
To learn more about the area of the triangle visit:
https://brainly.com/question/11952845.
#SPJ2
Log 1/10 how do you convert this without a calculator
Answer:
log(1/10) = -1
Step-by-step explanation:
Use the law of exponents and the meaning of logarithm.
1/10 = 10^-1
log(10^x) = x
So, you have ...
log(1/10) = log(10^-1)
log(1/10) = -1
If f(x)=4x-6 and g(x) vx+2 what is (f*g)(7)
Answer: The value of (f*g)(7) is 66.
Step-by-step explanation:
Given functions: [tex]f(x)= 4x-6\text{ and } g(x)=\sqrt{x+2}[/tex]
Since, product of two functions: [tex](u*v)(x)=u(x)\times v(x)[/tex]
[tex](f*g)(x)=f(x)\times g(x)\\\\=4x-6\times \sqrt{x+2}\\\\\Rightarrow\ (f*g)(x)=(4x-6) \sqrt{x+2}[/tex]
[tex](f*g)(7)=(4(7)-6)\sqrt{7+2}\\\\=(28-6)\sqrt{9}\\\\=22\times 3=66[/tex]
Hence, the value of (f*g)(7) is 66.
PLZ HELP 55 POINTS Two quantities, x and y, are related proportionally such that 3x=2y . Which equation shows the same proportional relationship? A x/y=3/2 B x/2=y/3 C x/3=y/2 D x/2=3/y
Answer:
B
Step-by-step explanation:
3x = 2y
One way to solve this is to simply plug in values. If we say the following:
x = 2
y = 3
Then, we can start testing.
A: [tex]x/y = 3/2[/tex]
by plugging 2 and 3 in, we see that A doesn't work.
B: x/2 = y/3
This works! First we should look at the other equations.
C: x/3 = y/2
Nope.
D: x/2 = 3/y
This also works, but only with certain numbers. If we were to make x = 4, and y = 6, this wouldn't work.
You could also find out all of this using algebra. so, our anwser is B.
Find the length S of the spiral (t cos(t), t sin(t)) for 0 ≤ t ≤ 3π. (Round your answer to three decimal places.) S =
The arc length is
[tex]S=\displaystyle\int_C\mathrm ds[/tex]
where C is the given curve and ds is the line element. C is defined on 0 ≤ t ≤ 3π by the vector function,
[tex]\mathbf r(t)=(t\cos t,t\sin t)[/tex]
so the line element is
[tex]\mathrm ds=\left\|\dfrac{\mathrm d\mathbf r(t)}{\mathrm dt}\right\|\,\mathrm dt[/tex]
[tex]\mathrm ds=\sqrt{\left(\dfrac{\mathrm d(t\cos t)}{\mathrm dt}\right)^2+\left(\dfrac{\mathrm d(t\sin t)}{\mathrm dt}\right)^2}\,\mathrm dt[/tex]
[tex]\mathrm ds=\sqrt{1+t^2}\,\mathrm dt[/tex]
So we have
[tex]S=\displaystyle\int_0^{3\pi}\sqrt{1+t^2}\,\mathrm dt\approx46.132[/tex]
