The portion of the parabola y²=4ax above the x-axis, where is form 0 to h is revolved about the x-axis. Show that the surface area generated is
A=8/3π√a[(h+a)³/²-a³/2]
Use the result to find the value of h if the parabola y²=36x when revolved about the x-axis is to have surface area 1000.
Answers
Answer:
See below for Part A.
Part B)
[tex]\displaystyle h=\Big(\frac{125}{\pi}+27\Big)^\frac{2}{3}-9\approx7.4614[/tex]
Step-by-step explanation:
Part A)
The parabola given by the equation:
[tex]y^2=4ax[/tex]
From 0 to h is revolved about the x-axis.
We can take the principal square root of both sides to acquire our function:
[tex]y=f(x)=\sqrt{4ax}[/tex]
Please refer to the attachment below for the sketch.
The area of a surface of revolution is given by:
[tex]\displaystyle S=2\pi\int_{a}^{b}r(x)\sqrt{1+\big[f^\prime(x)]^2} \,dx[/tex]
Where r(x) is the distance between f and the axis of revolution.
From the sketch, we can see that the distance between f and the AoR is simply our equation y. Hence:
[tex]r(x)=y(x)=\sqrt{4ax}[/tex]
Now, we will need to find f’(x). We know that:
[tex]f(x)=\sqrt{4ax}[/tex]
Then by the chain rule, f’(x) is:
[tex]\displaystyle f^\prime(x)=\frac{1}{2\sqrt{4ax}}\cdot4a=\frac{2a}{\sqrt{4ax}}[/tex]
For our limits of integration, we are going from 0 to h.
Hence, our integral becomes:
[tex]\displaystyle S=2\pi\int_{0}^{h}(\sqrt{4ax})\sqrt{1+\Big(\frac{2a}{\sqrt{4ax}}\Big)^2}\, dx[/tex]
Simplify:
[tex]\displaystyle S=2\pi\int_{0}^{h}\sqrt{4ax}\Big(\sqrt{1+\frac{4a^2}{4ax}}\Big)\,dx[/tex]
Combine roots;
[tex]\displaystyle S=2\pi\int_{0}^{h}\sqrt{4ax\Big(1+\frac{4a^2}{4ax}\Big)}\,dx[/tex]
Simplify:
[tex]\displaystyle S=2\pi\int_{0}^{h}\sqrt{4ax+4a^2}\, dx[/tex]
Integrate. We can consider using u-substitution. We will let:
[tex]u=4ax+4a^2\text{ then } du=4a\, dx[/tex]
We also need to change our limits of integration. So:
[tex]u=4a(0)+4a^2=4a^2\text{ and } \\ u=4a(h)+4a^2=4ah+4a^2[/tex]
Hence, our new integral is:
[tex]\displaystyle S=2\pi\int_{4a^2}^{4ah+4a^2}\sqrt{u}\, \Big(\frac{1}{4a}\Big)du[/tex]
Simplify and integrate:
[tex]\displaystyle S=\frac{\pi}{2a}\Big[\,\frac{2}{3}u^{\frac{3}{2}}\Big|^{4ah+4a^2}_{4a^2}\Big][/tex]
Simplify:
[tex]\displaystyle S=\frac{\pi}{3a}\Big[\, u^\frac{3}{2}\Big|^{4ah+4a^2}_{4a^2}\Big][/tex]
FTC:
[tex]\displaystyle S=\frac{\pi}{3a}\Big[(4ah+4a^2)^\frac{3}{2}-(4a^2)^\frac{3}{2}\Big][/tex]
Simplify each term. For the first term, we have:
[tex]\displaystyle (4ah+4a^2)^\frac{3}{2}[/tex]
We can factor out the 4a:
[tex]\displaystyle =(4a)^\frac{3}{2}(h+a)^\frac{3}{2}[/tex]
Simplify:
[tex]\displaystyle =8a^\frac{3}{2}(h+a)^\frac{3}{2}[/tex]
For the second term, we have:
[tex]\displaystyle (4a^2)^\frac{3}{2}[/tex]
Simplify:
[tex]\displaystyle =(2a)^3[/tex]
Hence:
[tex]\displaystyle =8a^3[/tex]
Thus, our equation becomes:
[tex]\displaystyle S=\frac{\pi}{3a}\Big[8a^\frac{3}{2}(h+a)^\frac{3}{2}-8a^3\Big][/tex]
We can factor out an 8a^(3/2). Hence:
[tex]\displaystyle S=\frac{\pi}{3a}(8a^\frac{3}{2})\Big[(h+a)^\frac{3}{2}-a^\frac{3}{2}\Big][/tex]
Simplify:
[tex]\displaystyle S=\frac{8\pi}{3}\sqrt{a}\Big[(h+a)^\frac{3}{2}-a^\frac{3}{2}\Big][/tex]
Hence, we have verified the surface area generated by the function.
Part B)
We have:
[tex]y^2=36x[/tex]
We can rewrite this as:
[tex]y^2=4(9)x[/tex]
Hence, a=9.
The surface area is 1000. So, S=1000.
Therefore, with our equation:
[tex]\displaystyle S=\frac{8\pi}{3}\sqrt{a}\Big[(h+a)^\frac{3}{2}-a^\frac{3}{2}\Big][/tex]
We can write:
[tex]\displaystyle 1000=\frac{8\pi}{3}\sqrt{9}\Big[(h+9)^\frac{3}{2}-9^\frac{3}{2}\Big][/tex]
Solve for h. Simplify:
[tex]\displaystyle 1000=8\pi\Big[(h+9)^\frac{3}{2}-27\Big][/tex]
Divide both sides by 8π:
[tex]\displaystyle \frac{125}{\pi}=(h+9)^\frac{3}{2}-27[/tex]
Isolate term:
[tex]\displaystyle \frac{125}{\pi}+27=(h+9)^\frac{3}{2}[/tex]
Raise both sides to 2/3:
[tex]\displaystyle \Big(\frac{125}{\pi}+27\Big)^\frac{2}{3}=h+9[/tex]
Hence, the value of h is:
[tex]\displaystyle h=\Big(\frac{125}{\pi}+27\Big)^\frac{2}{3}-9\approx7.4614[/tex]
You seem to have left out that 0 ≤ x ≤ h.
From y² = 4ax, we get that the top half of the parabola (the part that lies in the first quadrant above the x-axis) is given by y = √(4ax) = 2√(ax). Then the area of the surface obtained by revolving this curve between x = 0 and x = h about the x-axis is
[tex]2\pi\displaystyle\int_0^h y(x) \sqrt{1+\left(\frac{\mathrm dy(x)}{\mathrm dx}\right)^2}\,\mathrm dx[/tex]
We have
y(x) = 2√(ax) → y'(x) = 2 • a/(2√(ax)) = √(a/x)
so the integral is
[tex]4\sqrt a\pi\displaystyle\int_0^h \sqrt x \sqrt{1+\frac ax}\,\mathrm dx[/tex]
[tex]=\displaystyle4\sqrt a\pi\int_0^h (x+a)^{\frac12}\,\mathrm dx[/tex]
[tex]=4\sqrt a\pi\left[\dfrac23(x+a)^{\frac32}\right]_0^h[/tex]
[tex]=\dfrac{8\pi\sqrt a}3\left((h+a)^{\frac32}-a^{\frac32}\right)[/tex]
Now, if y² = 36x, then a = 9. So if the area is 1000, solve for h :
[tex]1000=8\pi\left((h+9)^{\frac32}-27\right)[/tex]
[tex]\dfrac{125}\pi=(h+9)^{\frac32}-27[/tex]
[tex]\dfrac{125+27\pi}\pi=(h+9)^{\frac32}[/tex]
[tex]\left(\dfrac{125+27\pi}\pi\right)^{\frac23}=h+9[/tex]
[tex]\boxed{h=\left(\dfrac{125+27\pi}\pi\right)^{\frac23}-9}[/tex]
Related Questions
What is the answer to this radical functions equation ASAP
Answers
Hope it help
Mark Brainly
-3/5a=2
a= ___ please help
Answers
Answer:
a=-3 1/3
Step-by-step explanation:
Robin, who is self-employed, contributes $4500/year into a Keogh account. How much will he have in the account after 30 years if the account earns interest at the rate of 2.5%/year compounded yearly?
Answers
Answer:
The amount that would be in the account after 30 years is $368,353
Step-by-step explanation:
Here, we want to calculate the amount that will be present in the account after 30 years if the interest is compounded yearly
We proceed to use the formula below;
A = [P(1 + r)^t-1]/r
From the question;
P is the amount deposited yearly which is $4,500
r is the interest rate = 2.5% = 2.5/100 = 0.025
t is the number of years which is 30
Substituting these values into the equation, we have;
A = [4500(1 + 0.025)^30-1]/0.025
A = [4500(1.025)^29]/0.025
A = 368,353.3309607034
To the nearest whole dollars, this is;
$368,353
Please answer this correctly without making mistakes
Answers
Answer:
$25-$9.9
Step-by-step explanation:
45/100
0.45*$25
$9.9
$25-$9.9
it cost 14.1
A function, f left parenthesis x right parenthesis comma models the depth of water in a wading pool that is filling at a rate of 11 gallons per minute. Which of these describes why f left parenthesis x right parenthesis can be considered a linear function? I. For every 1 minute interval, the depth of water in the wading pool increases by the same amount. II. The function grows by equal factors every minute. III. The slope of the function is constant.
Answers
Answer:
quiz let or brainy helps me just look up the chapter question and you will get the answer
Step-by-step explanation:
hope this helps
f(x) can be considered as a linear function because of the following conclusions -
1 → For every 1 minute interval, the depth of water in the wading pool increases by the same amount of 11 gallons/minute.
2 → The slope of the function is constant.
What is the general equation of a straight line?
The general equation of a straight line is -
y = mx + c
Where -
[m] is the slope of the line.
[c] is the y - intercept.
Given is the following statement representing a function - f(x), that models the depth of water in a wading pool that is filling at a rate of 11 gallons per minute.
Assume that we represent the depth of the water rate by [y] and the time in minutes by [m]. We can write the function f(x) as -
y = f(x) = 11m
This is a linear relation and its graph will be a straight line passing through origin.
From this equation, we can make the following conclusions -
1 → For every 1 minute interval, the depth of water in the wading pool increases by the same amount of 11 gallons/minute.
2 → The slope of the function is constant.
Therefore, f(x) can be considered as a linear function because of the following conclusions -
1 → For every 1 minute interval, the depth of water in the wading pool increases by the same amount of 11 gallons/minute.
2 → The slope of the function is constant.
To solve more questions on straight line graphs, visit the link below-
brainly.com/question/2954112
#SPJ6
Twelve of the 28 students in a class have a dog. What is the ratio of students who have a dog to students who do not?
Answers
Answer:
28/12
Step-by-step explanation:
I NEED HELP WHAT IS THE ANSWER FOR PART (A) AND PART (B) I’ll cash app or Venmo if I give me answers by today please help.
Answers
Answer:
9/2 is the slope of the graphed line.
The second statement is true.
Step-by-step explanation:
What is the measure ofEGE?
What is the measure ofCGF?
E
50
F
options for EGF are 40, 55, 65, 80
options for CGF are 50, 90, 95, 115
Answers
Step-by-step explanation:
Angle EGF = 0.5(180° - 50°) = 65°.
Angle CGF = 180° - Angle EGF = 115°.
A store has two different brands of laundry
Answers
Answer:
Step-by-step explanation:
I am sorry but please give detailed question
Answer:
Is there supposed to be a pic?
Step-by-step explanation:
Solve the equation.
3y + 11 = -16
Answers
Answer:
y= -9
Step-by-step explanation:
Answer:
y = -9
Step-by-step explanation:
Algebra:
3y + 11 = -16
-11 -11
3y = -27
÷ 3 ÷ 3
y = -9
please fast tell me
Answers
Answer:
1). Option (b)
2). Option (d)
3). Option (d)
Step-by-step explanation:
Question (1)
For Pythagoras triplet,
(Largest number)² = (Number 1)² + (Number 2)²
a). 5² = 5² + 2²
25 = 25 + 4
25 = 29
Not True.
b). 5² = 3² + 4²
25 = 9 + 16
25 = 25
True.
c). 10² = 1² + 5²
100 = 1 + 25
100 = 26
Not true.
d). 2² = 2²+ 2²
4 = 4 + 4
4 = 8
Not true.
Therefore, Option (b) is correct.
Question (2)
1 - [tex]\frac{1}{5}[/tex] = [tex]\frac{5}{5}-\frac{1}{5}[/tex]
= [tex]\frac{5-1}{5}[/tex]
= [tex]\frac{4}{5}[/tex]
Therefore, Option (d) is the answer.
Question (3)
Property of triangle → Sum of lengths of two sides of a triangle should be greater than the measure of third side.
a). 6 + 3 > 2 ⇒ 9 > 2 [True]
6 + 2 > 3 ⇒ 8 > 3 [True]
2 + 3 > 6 ⇒ 5 > 6 [False]
Triangle is not possible.
b). 2 + 8 > 3 → 10 > 3 [True]
8 + 3 > 2 → 11 > 2 [True]
2 + 3 > 8 → 5 > 8 [False]
Triangle is not possible.
c). 5.5 + 2.5 > 2.5 → 8 > 2.5 [True]
5.5 + 2.5 > 2.5 → 8 > 2.5 [True]
2.5 + 2.5 > 5.5 → 5 > 5.5 [False]
Triangle is not possible.
d). 3 + 6 > 7 → 9 > 7 [True]
3 + 7 > 6 → 10 > 6 [True]
7 + 6 > 3 → 13 > 3 [True]
These are the sides of a triangle.
Therefore, Option D is the answer.
A 15-foot statue casts a 20-foot shadow. How tall is a person who casts a 4-foot-long shadow?
Answers
Answer:
3 ft.
Step-by-step explanation:
15:20 and x:4 you can cross multiply or if you reduce 15:20, the answer is 3:4
Which gives the correct values for points A, B, C, and D? A number line going from negative 2 to negative 1. There are 5 equal spaces between the numbers. A = negative 1 and one-fifths, B = negative 1 and two-fifths, C = negative 1 and three-fifths, D = negative 1 and four-fifths A = negative 1 and one-fifths, B = negative 1 and four-fifths, C = negative 1 and three-fifths, D = negative 1 and two-fifths A = negative 1 and four-fifths, B = negative 1 and three-fifths, C = negative 1 and two-fifths, D = negative 1 and one-fifth A = negative 1 and four-fifths, B = negative 1 and one-fifth, C = negative 1 and three-fifths, D = negative 1 and two-fifths
or if you dont feel like reading all thaaaat-
Answers
Answer:
Step-by-step explanation:
(D).
Kevin and his children went into a restaurant and he bought $31.50 worth of hotdogs and drinks. Each hotdog costs $4.50 and each drink costs $2.25. He bought 3 times as many hotdogs as drinks.
Answers
Answer:
He bought 6 hotdogs and 2 drinks
Step-by-step explanation:
System of Equations
Kevin and his children went into a restaurant and bought $31.50 worth of hotdogs and drinks. Each hotdog costs $4.50 and each drink costs $2.25.
To solve the system of equations, we'll call the variables:
x = number of hotdogs
y = number of drinks
The first condition yields the equation:
4.50x + 2.25y = 31.50 [1]
It's also known he bought 3 times as many hotdogs as drinks, thus:
x = 3y [2}
Substituting [2] in [1]:
4.50(3y) + 2.25y = 31.50
Operating:
13.5y + 2.25y = 31.50
15.75y = 31.50
y = 31.50/15.75
y = 2
And
x = 3*2 = 6
He bought 6 hotdogs and 2 drinks
Three vehicles recorded the following information about their trips.
Van: 500 miles in 7.5 hours
Truck: 300 miles in 5 hours
Car: 400 miles in 5.5 hours
Find the unit rate of miles/hour for the Van.
Answers
Answer:96km in 1 hour requires a speed of 96km/h; 96km in 2 hours requires a speed of 96/2=48km/h.
You can travel at any speed between 48km/h and 96km/h to arrive in between 1 and 2 hours.
There is no sufficient info to solve the problem and answer the question.
Also, this fragment "Two bikers started at the same," is a nonsense, not allowable in Math.
Find the antiderivative of the velocity function.
1 rotation = 2pi radians = 2*3.14 radians = 6.28 radians
1 rotation per 8 seconds is the angular velocity 2pi%2F8 radians per second = 6.28%2F8 = 0.785 radians per second
hope this is helpful
Given the quadratic equation: 1/2x^2+3x−10=0
Answers
Answer:
x=2.3851648071345037,−8.385164807134505
Step-by-step explanation:
given that a||b and m<6 is 1/8 of m<4, find m<4 and m<6
Answers
Answer:
Supplementary Angles: if both angles are added = 180 °
Complementary Angles: if both angles are added = 90°
Step-by-step explanation:
Answer:
m<6 = 20*, m<4 = 160*
Step-by-step explanation:
2.m<6+m<4=180*
3. m<6+m<4=180*
4. m<6+8 x m<20
5.m<6 = 20*, m<4 = 160*
Find the LCM of the denominators in these fractions
5/6 and 1/14
Answers
Answer:
35/42 and 3/42
Step-by-step explanation:
Multiply by 3.
HOPE THIS HELPS :)
The LCM of the denominators in the fractions 5/6 and 1/14 is 42.
What is Least Common Multiple(LCM)?The least common multiple is defined as the least positive integer that is dividable by both given numbers.
A group's Least Common Multiple (LCM) is the smallest number that is a multiple of all the numbers.
To find the least common multiple (LCM) of two numbers, you can list the multiples of each number and find the smallest number that is a multiple of both.
The multiples of 6 are 6, 12, 18, 24, 30, and so on. The multiples of 14 are 14, 28, 42, 56, and so on. The smallest number that is a multiple of both 6 and 14 is 42, so the LCM of 6 and 14 is 42.
Therefore, the denominators in the fractions 5/6 and 1/14 have an LCM of 42.
To learn more about the Least Common Multiple(LCM) here :
https://brainly.com/question/17256135
#SPJ2
What are the coordinates of the image after point (4,-5) is reflected across the x-axis
Answers
Answer and Step-by-step explanation:
The x-axis is a horizontal line
^
|
|
(<-------------------------|-----------------------------> x
| ^ This line is the x-axis
|
V
^
|
|
(<---------------|--|--|--|--|--|--|--|--|--|--|---------> x
|
|
|
|
| A ● (4, -5)
V
The point is listed, labeled as A. To reflect, all we have to do is go up twice the absolute amount of the y value, so the absolute value of 5 times 2.
^
| A' ● (4, 5)
|
|
|
|
(<---------------|--|--|--|--|--|--|--|--|--|--|---------> x
|
|
|
|
| A ● (4, -5)
V
This new point is labelled as A'.
(4, 5) is the new coordinate.
#teamtrees #WAP (Water And Plant)
Factor x3 + 2x2 + x completely.
Answers
Answer:
[tex] {x}^{3} + 2 {x}^{2} + x[/tex]
[tex]x(x {}^{2} + 2x + 1)[/tex]
[tex]x(x + 1) {}(x + 1)[/tex]
[tex]x(x + 1) {}^{2} [/tex]
Answer:
C. x(x+1)2 on edu 2021
Step-by-step explanation:
1) 16% of what number is 14?
2) 52 is what percent of 156
Answers
Answer: first one answer is 2.24
second one answer is 81.12
how do i right the half of x pls help will give brainliesst answer
Answers
Answer:[tex]\frac{1}{2}[/tex]x or x/2
Step-by-step explanation:
What is 3/5 converted into a percent.
Answers
Answer:
60%
Step-by-step explanation:
multiply 3/5 by 20
Answer:
60%
since 100/100 is 100%, we just have to find a number that will make the denominator 5 equal to 100. That is 20 so we multiply 20 for both 3 and 5. This equals to 60/100, which is 60%
Please help pleaseeeeeeeeeeeeeeee
Answers
Answer:
y=2x+5
Step-by-step explanation:
This is a proportional relationship.The other one's are not true.
PLS Mark brainlist
Hope this helps:)
is 1/3, 7/21 proportion
Answers
Answer:
1/3
Step-by-step explanation:
Q. Penelope is told to clean all the windows at her house. After cleaning 9 windows her job is
30% complete. How many windows does she clean in all?
Answers
Answer:
30
Step-by-step explanation:
So we know that 9 windows is 30% so then we multiply 30 to get to the closest to 100 which is x3 so its 90%. Then you divide 30 by 9 which is 3.3 and round it to 3.
Help me graph this inequality
Answers
Answer:
Step-by-step explanation:
A Polynomial, p(x), has zeros when x = -2, x = 1/3, X = 3. What could be the equation of p(x)?
Answers
Answer:
(x+2)(x-1/3)(x-3)
Step-by-step explanation:
This could be a possible equation, the signs of the of the roots are always the opposite in the equation form.
A quantity of food would last a family of 5 for 21days. How long would the same quantity last a family of 7 if they all eat at the same rate?
Answers
5x21=105 the amount of food they have
105/7=15 days of food for a family of 7
will give brainliest!
Answers
Answer:
2/1=2
Step-by-step explanation: