Find a degree 3 polynomial with real coefficients having zeros 1
and 2−2i and a lead coefficient of 1. Write P in expanded form. Be sure to write the full equation, including P(x)=
9514 1404 393
Answer:
P(x) = x³ -5x² +12x -8
Step-by-step explanation:
If the coefficients are real, then the complex roots must be conjugates. The third root is 2+2i. For root r, (x -r) is a factor, so the factorization is ...
P(x) = (x -1)(x -2 +2i)(x -2 -2i) = (x -1)((x -2)² +4) = (x -1)(x^2 -4x +8)
Expanding further, we find ...
P(x) = x³ -5x² +12x -8
A hotel manager believes that 23% of the hotel rooms are booked. If the manager is right, what is the probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%
Answer:
0.9216 = 92.16% probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
A hotel manager believes that 23% of the hotel rooms are booked.
This means that [tex]p = 0.23[/tex]
Sample of 610 rooms
This means that [tex]n = 610[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.23[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.23*0.77}{610}} = 0.017[/tex]
What is the probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%?
p-value of Z when X = 0.23 + 0.03 = 0.26 subtracted by the p-value of Z when X = 0.23 - 0.03 = 0.2. So
X = 0.26
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.26 - 0.23}{0.017}[/tex]
[tex]Z = 1.76[/tex]
[tex]Z = 1.76[/tex] has a p-value of 0.9608
X = 0.2
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.2 - 0.23}{0.017}[/tex]
[tex]Z = -1.76[/tex]
[tex]Z = -1.76[/tex] has a p-value of 0.0392
0.9608 - 0.0392 = 0.9216
0.9216 = 92.16% probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%
circle A has a center of (2,3) and a radius of 5 and circle B has a center of (1,4) and a radius of 10. What steps will help show that circle A is similar to circle B
Answer:
12
Step-by-step explanation:
Suppose 42% of the population has myopia. If a random sample of size 442 is selected, what is the probability that the proportion of persons with myopia will differ from the population proportion by less than 3%
Answer:
0.7994 = 79.94% probability that the proportion of persons with myopia will differ from the population proportion by less than 3%.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Suppose 42% of the population has myopia.
This means that [tex]p = 0.42[/tex]
Random sample of size 442 is selected
This means that [tex]n = 442[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.42[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.42*0.58}{442}} = 0.0235[/tex]
What is the probability that the proportion of persons with myopia will differ from the population proportion by less than 3%?
Proportion between 0.42 + 0.03 = 0.45 and 0.42 - 0.03 = 0.39, which is the p-value of Z when X = 0.45 subtracted by the p-value of Z when X = 0.39.
X = 0.45
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.45 - 0.42}{0.0235}[/tex]
[tex]Z = 1.28[/tex]
[tex]Z = 1.28[/tex] has a p-value of 0.8997
X = 0.39
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.39 - 0.42}{0.0235}[/tex]
[tex]Z = -1.28[/tex]
[tex]Z = -1.28[/tex] has a p-value of 0.1003
0.8997 - 0.1003 = 0.7994
0.7994 = 79.94% probability that the proportion of persons with myopia will differ from the population proportion by less than 3%.
Consider the functions z = 4 e^x ln y, x = ln (u cos v), and y = u sin v.
Express dz/du and dz/dv as functions of u and y both by using the Chain Rule and by expressing z directly in terms of u and v before differentiating.
Answer:
remember the chain rule:
h(x) = f(g(x))
h'(x) = f'(g(x))*g'(x)
or:
dh/dx = (df/dg)*(dg/dx)
we know that:
z = 4*e^x*ln(y)
where:
y = u*sin(v)
x = ln(u*cos(v))
We want to find:
dz/du
because y and x are functions of u, we can write this as:
dz/du = (dz/dx)*(dx/du) + (dz/dy)*(dy/du)
where:
(dz/dx) = 4*e^x*ln(y)
(dz/dy) = 4*e^x*(1/y)
(dx/du) = 1/(u*cos(v))*cos(v) = 1/u
(dy/du) = sin(v)
Replacing all of these we get:
dz/du = (4*e^x*ln(y))*( 1/u) + 4*e^x*(1/y)*sin(v)
= 4*e^x*( ln(y)/u + sin(v)/y)
replacing x and y we get:
dz/du = 4*e^(ln (u cos v))*( ln(u sin v)/u + sin(v)/(u*sin(v))
dz/du = 4*(u*cos(v))*(ln(u*sin(v))/u + 1/u)
Now let's do the same for dz/dv
dz/dv = (dz/dx)*(dx/dv) + (dz/dy)*(dy/dv)
where:
(dz/dx) = 4*e^x*ln(y)
(dz/dy) = 4*e^x*(1/y)
(dx/dv) = 1/(cos(v))*-sin(v) = -tan(v)
(dy/dv) = u*cos(v)
then:
dz/dv = 4*e^x*[ -ln(y)*tan(v) + u*cos(v)/y]
replacing the values of x and y we get:
dz/dv = 4*e^(ln(u*cos(v)))*[ -ln(u*sin(v))*tan(v) + u*cos(v)/(u*sin(v))]
dz/dv = 4*(u*cos(v))*[ -ln(u*sin(v))*tan(v) + 1/tan(v)]
Suppose that the IQ of a randomly selected student from a university is normal with mean 115 and standard deviation 25. Determine the interval of values that is centered at the mean and for which 50% of the students have IQ's in that interval.
Answer:
The interval is [98,132]
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Normal with mean 115 and standard deviation 25.
This means that [tex]\mu = 115, \sigma = 25[/tex]
Determine the interval of values that is centered at the mean and for which 50% of the students have IQ's in that interval.
Between the 50 - (50/2) = 25th percentile and the 50 + (50/2) = 75th percentile.
25th percentile:
X when Z has a p-value of 0.25, so X when Z = -0.675.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-0.675 = \frac{X - 115}{25}[/tex]
[tex]X - 115 = -0.675*25[/tex]
[tex]X = 98[/tex]
75th percentile:
X when Z has a p-value of 0.75, so X when Z = 0.675.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.675 = \frac{X - 115}{25}[/tex]
[tex]X - 115 = 0.675*25[/tex]
[tex]X = 132[/tex]
The interval is [98,132]
Step by step solution help me pls
Step-by-step explanation:
Recall that
[tex]1 + \tan^2 x = \sec^2 x[/tex]
and
[tex]\dfrac{d}{dx}(\tan x) = \sec^2 x[/tex]
so that
[tex]\displaystyle \int \tan^2 x = \int (\sec^2 x - 1)dx[/tex]
[tex]\:\:\:\:\:\:\:\:\:=\int \sec^2 xdx - \int dx[/tex]
[tex]\:\:\:\:\:\:\:\:\:=\tan x - x + C[/tex]
where C is the constant of integration.
Help please somebody ASAP
Answer:
[tex]\frac{-2x+11}{(x-4)(x+1)}[/tex]
Step-by-step explanation:
I don't think we can factor this so we'll have to multiply to make the denominators the same
[tex]\frac{3(x+1)}{(x^2-3x-4)(x+1)}-\frac{2(x^2-3x-4)}{(x+1)(x^2-3x-4)}\\\\\frac{3x+3-(2x^2-6x-8)}{(x^2-3x-4)(x+1)}=\frac{-2x^2+9x+11}{(x^2-3x-4)(x+1)}\\-2x^2+9x+11=(x+1)(-2x+11)\\\\x^2-3x-4=(x+1)(x-4)\\\frac{(x+1)(-2x+11)}{(x+1)(x-4)(x+1)}=\frac{-2x+11}{(x-4)(x+1)}[/tex]
Write an expression for the sequence of operations described below.
divide s by q, add r to the result, then triple what you have
Do not simplify any part of the expression.
Answer:
3( [tex]\frac{s}{q}[/tex] + r)
it's tooooo easy who wants brain list
Answer:
1) Isosceles
2) Acute
3) Right angled
4( Obtuse
5) Equilateral
anna needs at least $1000 to pay her bills this week.she has $250 in the bank and makes $15 an hour at her job.how many hours does she have to work thus week in order to pay her bills
Use the definition of a Taylor series to find the first four nonzero terms of the series for f(x) centered at the given value of a. (Enter your answers as a comma-separated list.)
f(x) = 7/(1+x), a = 2
Find the Maclaurin series for f(x) using the definition of a Maclaurin series. [Assume that f has a power series expansion. Do not show that Rn(x) → 0.]
f(x) = e−5x
f(x)=
[infinity]
n = 0
=
Find the associated radius of convergence R.
R =
Answer:
A) [ 7/3, (-7/9)(x/2), 7/27(x-2)^2, (-7/81)(x-2)^3 ]
B) attached below
Step-by-step explanation:
A) Using the definition of a Taylor series
The first four nonzero terms of the series for f(x) = 7/ (1 +x), a = 2
= [ 7/3, (-7/9)(x/2), 7/27(x-2)^2, (-7/81)(x-2)^3 ]
attached below is the detailed solution
B) Finding Maclaurin series for f(x)
f(x) = e^-5x
attached below
Associated radius of convergence = ∞ ( infinity )
Write the equation of the line with the given conditions. passing through (-1, -7) and perpendicular to the line with equation 4x + 5y = 31
Answer:
y = 5/4 x - 23/4
Step-by-step explanation:
4x + 5y = 31
5y = - 4x +31
y = -4/5 x + 31/5
⊥ slope = 5/4
-7 = 5/4 (-1) + B
-28 = -5 + 4b
-23 = 4B
b = -23/4
One angle of a triangle is twice as large as another. The measure of the third angle is 60° more than that of the smallest angle. Find the measure of each angle.
The measure of the smallest angle is º
Please help :)
Answer:
The measure of the smallest angle is 30º
Step-by-step explanation:
Let the angles be:
[tex]x \to[/tex] the first angle (the smallest)
[tex]y \to[/tex] the second angle
[tex]z \to[/tex] the third angle
So, we have:
[tex]y = 2x[/tex]
[tex]z=x + 60[/tex]
Required
Find x
The angles in a triangle is:
[tex]x + y +z = 180[/tex]
Substitute values for y and z
[tex]x + 2x +x + 60 = 180[/tex]
[tex]4x + 60 = 180[/tex]
Collect like terms
[tex]4x = 180-60[/tex]
[tex]4x = 120[/tex]
Divide by 4
[tex]x = 30[/tex]
By recognizing each series below as a Taylor series evaluated at a particular value of x, find the sum of each convergent series.
A. 1 + 1/5 + (1/5)^2 + (1/5)^3 + (1/5)^4 +.....+ (1/5)^n + .... = _____.
B. 1 + 5 + 5^2/2! + 5^3/3! + 5^4/4! +....+ 5^n/n! +....= _____.
The first sum is a geometric series:
[tex]1+\dfrac15+\dfrac1{5^2}+\dfrac1{5^3}+\cdots+\dfrac1{5^n}+\cdots=\displaystyle\sum_{n=0}^\infty\frac1{5^n}[/tex]
Recall that for |x| < 1, we have
[tex]\dfrac1{1-x}=\displaystyle\sum_{n=0}^\infty x^n[/tex]
Here we have |x| = |1/5| = 1/5 < 1, so the first sum converges to 1/(1 - 1/5) = 5/4.
The second sum is exponential:
[tex]1+5+\dfrac{5^2}{2!}+\dfrac{5^3}{3!}+\cdots+\dfrac{5^n}{n!}+\cdots=\displaystyle\sum_{n=0}^\infty \frac{5^n}{n!}[/tex]
Recall that
[tex]\exp(x)=\displaystyle\sum_{n=0}^\infty\frac{x^n}{n!}[/tex]
which converges everywhere, so the second sum converges to exp(5) or e⁵.
Find the numerical value of each expression. (Round your answers to five decimal places.) (a) sinh(ln(5)) (b) sinh(5)
sinh(ln(4)) = (exp(ln(4)) - exp(-ln(4)))/2 = (4 - 1/4)/2 = 15/8 = 1.875
sinh(4) = (exp(4) - exp(-4))/2 ≈ 27.28992
Value of the expression in which each variable was swapped out with a number from its corresponding domain sinh (l5)
How do you determine an expression's numerical value?sinh (5)
=sinh(1.6094) =2.39990 rad
=sinh(1.6094) =2.3
By doing the following, you may determine the numerical value of an algebraic expression: Replace each variable with the specified number. Then, enter your score in your team's table.
Analyze expressions that are linear.Multi-variable expressions should be evaluated.Analyze expressions that are not linear.Value of the expression in which each variable was swapped out with a number from its corresponding domain. In the case of a number with only one digit, referring to the numerical value associated with a digit by its "value" is a convenient shorthand.
To learn more about Value of the expression refer to:
https://brainly.com/question/13961297
#SPJ2
what is the value of x? 4/5x-1/10=3/19
Answer:
x=[tex]\frac{1}{2}[/tex]
Step-by-step explanation:
Hi there!
We are given the following equation:
[tex]\frac{4x}{5}[/tex]-[tex]\frac{1}{10}[/tex]=[tex]\frac{3}{10}[/tex]
and we need to find the value of x
To do this, we need to isolate the value of x with a coefficient of 1 (1x) on one side. The value of x, or everything else is on the other side
So let's get rid of [tex]\frac{1}{10}[/tex] from the left side by adding [tex]\frac{1}{10}[/tex] to both sides (-[tex]\frac{1}{10}[/tex]+[tex]\frac{1}{10}[/tex]=0).
[tex]\frac{4x}{5}[/tex]-[tex]\frac{1}{10}[/tex]=[tex]\frac{3}{10}[/tex]
+[tex]\frac{1}{10}[/tex] +[tex]\frac{1}{10}[/tex]
___________
[tex]\frac{4x}{5}[/tex]=[tex]\frac{3}{10}[/tex]+[tex]\frac{1}{10}[/tex]
as the fractions on the right side both have the same denominator, we can add them together
[tex]\frac{4x}{5}[/tex]=[tex]\frac{4}{10}[/tex]
Now we need to have the value of 1x. Currently we have [tex]\frac{4x}{5}[/tex].
In order to get x with a coefficient of 1, multiply both sides by the reciprocal of [tex]\frac{4}{5}[/tex], which is [tex]\frac{5}{4}[/tex]
[tex]\frac{5}{4}[/tex]×[tex]\frac{4x}{5}[/tex]=[tex]\frac{4}{10}[/tex]*[tex]\frac{5}{4}[/tex]
which simplifies down to
x=[tex]\frac{20}{40}[/tex]
Now reduce the fraction by dividing the numerator and denominator both by 20
x=[tex]\frac{1}{2}[/tex]
Hope this helps!
Question 8 of 9
Use a calculator to find the correlation coefficient of the data set.
х
у
2
15
6
13
7.
9
8
on 0
12 5
O A. -0.909
OB. 0.909
Ο Ο Ο
O C. 0.953
D. -0.953
Actual data table :
X __ y
2 15
6 13
7 9
8 8
12 5
Answer:
0.953
Step-by-step explanation:
The question isnt well formatted :
The actual data:
X __ y
2 15
6 13
7 9
8 8
12 5
Using a correlation Coefficient calculator, the correlation Coefficient obtained by fitting the data is 0.953 which depicts a strong linear correlation between the x and y variable. This shows that the value of y increases with a corresponding increase in x values and vice versa.
Solve the simultaneous equations
2x+3y20
2x+5=10
Answer:
[tex]x=\frac{5}{2} \\y=5[/tex]
( 5/2, 2 )
Step-by-step explanation:
Solve by substitution method:
[tex]2x+5=10\\\2x+3y=20[/tex]
Solve [tex]2x+5=10[/tex] for [tex]x[/tex]:
[tex]2x+5=10[/tex]
[tex]2x=10-5[/tex]
[tex]2x=5[/tex]
[tex]x=5/2[/tex]
Substitute [tex]5/2[/tex] for [tex]x[/tex] in [tex]2x+3y=20[/tex]:
[tex]2x+3y=20[/tex]
[tex]2(\frac{5}{2} )+3y=20[/tex]
[tex]3y+5=20[/tex]
[tex]3y=20-5[/tex]
[tex]3y=15[/tex]
[tex]y=15/3[/tex]
[tex]y=5[/tex]
∴ [tex]x=\frac{5}{2}[/tex] and [tex]y=5[/tex]
hope this helps....
what is the correct equation ?
Answer:
B
Step-by-step explanation:
B is the correct equation
haydenkyletoddhaydenkyletodd
The shaded region R in diagram below is enclosed by y-axis, y = x^2 - 1 and y = 3.
Determine the volume of the solid generated when the shaded region R is revolved
about x = -1 by using Disk method.
Cross sections of the volume are washers or annuli with outer radii x(y) + 1, where
y = x(y) ² - 1 ==> x(y) = √(y + 1)
and inner radii 1. The distance between the outermost edge of each shell to the axis of revolution is then 1 + √(y + 1), and the distance between the innermost edge of R on the y-axis to the axis of revolution is 1.
For each value of y in the interval [-1, 3], the corresponding cross section has an area of
π (1 + √(y + 1))² - π (1)² = π (2√(y + 1) + y + 1)
Then the volume of the solid is the integral of this area over [-1, 3]:
[tex]\displaystyle\int_{-1}^3\pi y\,\mathrm dy = \frac{\pi y^2}2\bigg|_{-1}^3 = \boxed{4\pi}[/tex]
[tex]\displaystyle\int_{-1}^3 \pi\left(2\sqrt{y+1}+y+1\right)\,\mathrm dy = \pi\left(\frac43(y+1)^{3/2}+\frac{y^2}2+y\right)\bigg|_{-1}^3 = \boxed{\frac{56\pi}3}[/tex]
When f(x) = 4 , what is the value of ?
A. 0
B. 2
C. 3
D. 4
Which of the following must be equal to 30% of x?
3x
(A)
1,000
3x
(B)
100
3x
(C)
10
(D) 3x
Answer:
You can go ahead with option D
Step-by-step explanation:
30% of x will be 3xI really need help with this problem
Step-by-step explanation:
(x)+(x+1)<832x+1<832x<83-1x<82/2x<41hope it helps.stay safe healthy and happy....Answer:
[tex]x<41[/tex]
Step-by-step explanation:
[tex](x)+(x+1)<83[/tex]
simplify both sides
[tex]2x+1<83[/tex]
subtract one from the both sides to isolate the variable
[tex]2x<82[/tex]
divide both sides by 2 to isolate the variable
[tex]x<41[/tex]
Suppose you just received a shipment of 14 televisions. Three of the televisions are defective. If two televisions are randomly selected , compute the probability that both televisions work. What is the probability at least one of the two televisions does not work?
Answer:
Probability of defective televisions : Now, If two televisions are randomly selected, then the probability that both televisions work. Hence, the probability that both televisions work is 0.5289 . Hence, the probability at least one of the two televisions does not work is 0.4711.
A square coffee shop has sides that are 10 meters long. What is the coffee shop's area?
square meters
100
SOLUTION:
10•10= 100
The fraction
8
produces a repeating decimal.
0.375
O A. True
O B. False
It is false
Step-by-step explanation:
Hope it will help you
A group of 40 bowlers showed that their average score was 192. Assume the population standard deviation is 8. Find the 95% confidence interval of the mean score of all bowlers.
Answer:
[tex]CI=189.5,194.5[/tex]
Step-by-step explanation:
From the question we are told that:
Sample size [tex]n=40[/tex]
Mean [tex]\=x =192[/tex]
Standard deviation[tex]\sigma=8[/tex]
Significance Level [tex]\alpha=0.05[/tex]
From table
Critical Value of [tex]Z=1.96[/tex]
Generally the equation for momentum is mathematically given by
[tex]CI =\=x \pm z_(a/2) \frac{\sigma}{\sqrt{n}}[/tex]
[tex]CI =192 \pm 1.96 \frac{8}{\sqrt{40}}[/tex]
[tex]CI=192 \pm 2.479[/tex]
[tex]CI=189.5,194.5[/tex]
Find the area of the surface generated when the given curve is revolved about the y-axis. The part of the curve y=4x-1 between the points (1, 3) and (4, 15)
Answer:
Step-by-step explanation:
Let take a look at the given function y = 4x - 1 whose point is located between (1,3) and (4,15) on the graph.
Here, the function of y is non-negative. Now, expressing y in terms of x in y = 4x- 1
4x = y + 1
[tex]x = \dfrac{y+1}{4}[/tex]
[tex]x = \dfrac{1}{4}y + \dfrac{1}{4}[/tex]
By integration, the required surface area in the revolve is:
[tex]S = \int^{15}_{ 3} 2 \pi g (y) \sqrt{1+g'(y^2) \ dy }[/tex]
where;
g(y) = [tex]x = \dfrac{1}{4}y + \dfrac{1}{4}[/tex]
∴
[tex]S = \int^{15}_{ 3} 2 \pi \Big( \dfrac{1}{4}y + \dfrac{1}{4}\Big) \sqrt{1+\Bigg(\Big( \dfrac{1}{4}y + \dfrac{1}{4}\Big)'\Bigg)^2 \ dy }[/tex]
[tex]S = \dfrac{1}{2} \pi \int^{15}_{ 3} (y+1) \sqrt{1+\Bigg(\Big( \dfrac{1}{4}\Big ) \Bigg)^2 \ dy } \\ \\ \\ S = \dfrac{1}{2} \pi \int^{15}_{ 3} (y+1) \dfrac{\sqrt{17}}{4} \ dy[/tex]
[tex]S = \dfrac{\sqrt{17}}{8} \pi \int^{15}_{ 3} (y+1) \ dy[/tex]
[tex]S = \dfrac{\sqrt{17} \pi}{8} (\dfrac{1}{2}(y+1)^2)\Big|^{15}_{3} \\ \\ S = \dfrac{\sqrt{17} \pi}{8} (\dfrac{1}{2}(15+1)^2-\dfrac{1}{2}(3+1)^2 ) \\ \\ S = \dfrac{\sqrt{17} \pi}{8} *120 \\ \\\mathbf{ S = 15 \sqrt{17}x}[/tex]