Answer:
It is the first three options. A,B,C or 1,2,3
Step-by-step explanation:
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.
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]
45% of a number is 180
Step-by-step explanation:
45% of number = 180
=> 100% of number = 180 * (100/45) = 400.
Hence the number is 400.
Perform the following operation
and express the answer in
scientific notation.
6.300x10^-5 – 7.200x10^-3
[?]*10
Answer:
Step-by-step explanation:
6.3 x10^-5 -7.200 x10^-3= - 0.007137=7.137x10-3
Answer:-7.137 x 10^-3
Step-by-step explanation:
which statement is true regarding the functions on the graph?
Answer:
f(3)=g(3)
Step-by-step explanation:
the only one i see is that
f(3)=g(3)
because the two functions intersect there
that means the two values are the same
1. Assume that men’s weights are normally distributed with a mean given by = 172lb and a standard deviation given by =29lb. Using the Central Limit Theorem to solve the following exercises(1) If 36 men are randomly selected, find the probability that they have a mean weight greater than 160lb.(2) If 81 men randomly selected, find the probability that they have a mean weight between 170lb and 175lb.
Answer:
1) 0.99348
2) 0.55668
Step-by-step explanation:
Assume that men’s weights are normally distributed with a mean given by = 172lb and a standard deviation given by =29lb. Using the Central Limit Theorem to solve the following exercises
When given a random number of samples, we use the z score formula:
z-score is z = (x-μ)/σ/√n where
x is the raw score
μ is the population mean
σ is the population standard deviation.
(1) If 36 men are randomly selected, find the probability that they have a mean weight greater than 160lb.
For x > 160 lb
z = 160 - 172/29/√36
z = 160 - 172/29/6
z = -2.48276
Probability value from Z-Table:
P(x<160) = 0.0065185
P(x>160) = 1 - P(x<160) = 0.99348
(2) If 81 men randomly selected, find the probability that they have a mean weight between 170lb and 175lb.
For x = 170 lb
z = 170 - 172/29/√81
z = 170 - 172/29/9
z = -0.62069
Probability value from Z-Table:
P(x = 170) = 0.2674
For x = 175 lb
z = 175 - 172/29/√36
z = 175- 172/29/6
z = 0.93103
Probability value from Z-Table:
P(x = 175) = 0.82408
The probability that they have a mean weight between 170lb and 175lb is calculated as:
P(x = 175) - P(x = 170)
0.82408 - 0.2674
= 0.55668
Can someone help me with 3 and 4
Answer:
x÷3+10 (if x=15)
15÷3+10
5+10
15
HELP IM IN CLASS DOING IT RIGHT NOW The absolute value of any number is always positive. True False
Answer:
True
Step-by-step explanation:
Answer:
[tex] \huge\purple{TRUE}[/tex]
Step-by-step explanation:
The absolute value of any number is always positive.
f(x)=2x 5 −13x 4 +22x 3 −187x 2 −160x+336
Answer:
i think 3
Step-by-step explanation:
In how many zeros does 75! end?
-16.3=w+6.1 first to answer will earn brainiest!
Answer:
w = - 22.4
Step-by-step explanation:
w + 6.1 = -16.3
**subtract 6.1 on both sides to isolate w:
w = -16.3 - 6.1
w = -22.4
Answer:i wont answer it because the other guy is right
Step-by-step explanation:
21. Transportation A youth group with 26 members is going skiing. Each of the five
chaperones will drive a van or sedan. The vans can seat seven people, and the
sedans can seat five people. Assuming there are no empty seats, how many of each
type of vehicle could transport all 31 people to the ski area in one trip?
Answers:
2 sedans and 3 vans
=====================================================
Work Shown:
s = number of sedans
v = number of vans
1 sedan = 5 seats
s sedans = 5s seats
1 van = 7 seats
v vans = 7v seats
5s+7v = all seats
5s+7v = 31
Let's go through all the values of s to see which values of v work.
If s = 0, then the equation turns into 7v = 31, but the solution for v isn't an integer.If s = 1, then the equation turns into 5+7v = 31 and that solves to v = 26/7 = 3.71 which also isn't an integerIf s = 2, then the equation becomes 10+7v = 31 and that solves to v = 3. So we found the answer. This means we need 2 sedans and 3 vans.As a check:
2 sedans = 5*2 = 10 seats
3 vans = 7*3 = 21 seats
10+21 = 31 seats total
This confirms the answer.
The number of vans used is three and the number of sedans is two
Let :
v represent the number of vans
s represent the number of sedans
The following equations can be gotten
7v + 5s = 31 equation 1
v + s = 5 equation 2
The elimination method would be used to solve for v and s
Multiply equation 2 by 7
7v + 7s = 35 equation 3
Subtract equation 1 from 3
2s = 4
s = 4/2
s = 2
Substitute for s in equation 2
v + 2 = 5
v = 5 - 2
v = 3
To learn more about simultaneous equations, please check: brainly.com/question/23589883?referrer=searchResults
Which shows the use of the associative and commutative properties to make simplifying 3.2 + 20 – 3+ 4.8 + 19 easier?
Answer:
B
Step-by-step explanation:
(3.2+4.8)+[20+19+(-4)]
8. +. 47. -4
=43
what type of transformation maps abc onto def
Answer:
The answer is translation :)
Select the expressions that are equivalent to 34
Answer:
81 9^2
Step-by-step explanation:
3•3= 9
3•3=9
9•9=81
and 9•9=81
are any of these equations linear or nonlinear if yes what is the standard form
a. y=-7+6x
b. y=2x+5
Answer:
both are linear
a) 6x - y = 7
b) 2x - y = -5
Step-by-step explanation:
which of the following represents the equation with a slope of 3 and a y-intercept of 2?
Answer:
c is the correct answer
Step-by-step explanation:
When a gas is kept at a constant temperature and pressure on it changes, its volume changes according to the following formula, known as Boyle’s law
where P1 and V1 are the pressure (in atm) and the volume (in litres) at the beginning, and P2 and V2 are the pressure and the volume at the end. Find the final pressure P2 if V1 = 1.5 litres, P1 = 4.5 atm and V2 = 3.5 litres. Round to the nearest tenth of a atm.
Answer: Approximately 1.9 atm
============================================
Work Shown:
[tex]P_1*V_1 = P_2*V_2 \ \text{ ... Boyle's Law}\\\\4.5*1.5 = P_2*3.5\\\\6.75 = P_2*3.5\\\\P_2*3.5 = 6.75\\\\P_2 = \frac{6.75}{3.5}\\\\P_2 \approx 1.92857142857142\\\\P_2 \approx 1.9\\\\[/tex]
If the volume is 3.5 liters, then the pressure is approximately 1.9 atm.
Note the increase in volume leads to the reduction of pressure, and vice versa. The two variables have an inverse relationship.
-----------
As a check,
[tex]P_1*V_1 = P_2*V_2\\\\4.5*1.5 \approx 1.9*3.5\\\\6.75 \approx 6.65\\\\[/tex]
We don't get the exact thing on both sides, but the two sides are close enough. We have rounding error due to P2 being not exact.
A more accurate check could be
[tex]P_1*V_1 = P_2*V_2\\\\4.5*1.5 \approx 1.92857*3.5\\\\6.75 \approx 6.749995\\\\[/tex]
which has the two sides much closer to one another. This helps us verify the answer.
Kevin and his children went into a restaurant and he bought 31.50
um kevin bought 31.50 of what? food?
The population of Garden City in 1995 was 2,400. In 200, the population was 4,000. Write a linear equation in slope-intercept form that represents this data.
Answer:
[tex]y = 320x +2080[/tex]
Step-by-step explanation:
Given
Population in 1995 = 2400
Population in 2000 = 4000
Required
Determine the linear equation
Let the years be represented with x.
In 1995, x = 1 i.e. the first year
In 2000, x = 6
Let y represents the population
When x = 1; y = 2400
When x = 6; y = 4000
First, we calculate the slope (m)
[tex]m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]
[tex]m = \frac{4000 - 2400}{6 - 1}[/tex]
[tex]m = \frac{1600}{5}[/tex]
[tex]m = 320[/tex]
Next, we calculate the line equation as follows:
[tex]y - y_1 = m(x - x_1)[/tex]
[tex]y - 2400 = 320(x - 1)[/tex]
[tex]y - 2400 = 320x - 320[/tex]
[tex]y = 320x - 320 + 2400[/tex]
[tex]y = 320x +2080[/tex]
1 1/2 x 4 1/4 = ?
PLZ ANSWER QUICKLY
A student is training for the track team during the first three months of the year by
running for 30 minutes every day, while averaging 5 miles each day. Select the graph
that correctly shows the total miles the student ran during the time of his training
program.
1)
Hous
500
2)
200
Hours
10
23
8
50
3)
Answer:
uhhh
Step-by-step explanation:
Answer:
This question is to perfect to answer.
what is this answer!!!!!!!!
Step-by-step explanation:
what is this answer
(3x + 40) + (5x - 52) = 180°
8x - 12 = 180°
8x = 180 + 12
8x = 192
8x = 24
x = 3
Max bought a new pair of basketball shoes that were on sale for 25% off. If the regular price of the shoes was $75.95, what is the amount of discount?
Simplify each expression. (Will Give Brainlest)
Answer:
0.88
Step-by-step explanation:
-5.37 + 8.14 - 1.89
-5.37 + 6.25
= 0.88
Step-by-step explanation:
please i worked on paper worksheet
please see it
At a sale, dresses were sold for $22 each. This price was 55% of a dress's original price. How much did a dress originally cost? Answer: Submit Answer attempt 1 out o Privacy Policy Terms of Service acer
Answer:
$9.90
Step-by-step explanation:
Aden started with 6 cups of water. Throughout the day he drank the following amounts: 1 1/3 cups, 1 1/2 cups, 1 2/3 cups, and 3/4 cup. How many cups of water are left?
A. 2/3
B. 3/4
C. 1 1/3
D. 1/4
Answer:
B. 3/4 cup of water
Step-by-step explanation:
1 1/3 + 1 1/2 + 1 2/3 + 3/4 = 5 1/4
6 - 5 1/4 = 3/4
Answer: B or 3/4
Step-by-step explanation:
ok first add all the amounts he drank together
1 1/3 + 1 1/2 + 1 2/3 + 3/4
because the denominators are all different, you have to change them to a common denominator, which is 12. i've also changed them to improper fractions.
1 1/3 = 4/3 = 16/12 1 1/2 = 3/2= 18/12 1 2/3 = 5/3= 20/12 3/4 = 9/12
now add them all together
16/12 + 18/12 + 20/12 + 9/12 = 63/12
now convert the original 6 cups to an improper fraction with the denominator of 12
6 = 72/12
now subtract 63/12 (the amount he drank) from 72/12 (the amount he started with)
72/12 - 63/12 = 9/12
9/12 is able to be simplified to 3/4
so the correct answer is B, or 3/4
he;ppppppppppppppppppppppppppppppppppppppppppppppppppppp
Answer:
y = 64
Step-by-step explanation:
The angles are supplementary, that is sum to 180° , thus
2(x + 6) + y = 180 ← substitute x = 52
2(52 + 6) + y = 180
2(58) + y = 180
116 + y = 180 ( subtract 116 from both sides )
y = 64
Lydia receives a $2,000 gift and wants to open a savings account. Which bank interest would be the best for her if the current inflation rate is 3.5%?
Answer:
the best interest rate would be a minimum of 3.5% annual interest
Step-by-step explanation:
An inflation rate of 3.5% would mean that the buying power of Lydia's money would decrease by 3.5% every single year. Therefore, the best interest rate would be a minimum of 3.5% annual interest. That way she would at least maintain the same buying power with her money as the day that she first placed it in the account. Any interest rate higher than 3.5% would be even better as Lydia will begin to make a profit from her savings.
Which unit rate is the lowest price per ounce out of 25 ounces of potato chips fo 3.49$ or 45 ounces of potato chips for 4.79$
Answer: choice A : 3.49/25 = 0.139 rounds to 14 cents per oz
choice B ; 4.79/40 = 0.119 rounds to 12 cents per oz. lowest price is choice B
how many milligrams (mg) are
in a levothyroxine 88mcg tablet?