(a) See the attached sketch. Each shell will have a radius <em>y</em> chosen from the interval [2, 4], a height of <em>x</em> = 2/<em>y</em>, and thickness ∆<em>y</em>. For infinitely many shells, we have ∆<em>y</em> converging to 0, and each super-thin shell contributes an infinitesimal volume of
2<em>π</em> (radius)² (height) = 4<em>πy</em>
Then the volume of the solid is obtained by integrating over [2, 4]:

(b) See the other attached sketch. (The text is a bit cluttered, but hopefully you'll understand what is drawn.) Each shell has a radius 9 - <em>x</em> (this is the distance between a given <em>x</em> value in the orange shaded region to the axis of revolution) and a height of 8 - <em>x</em> ³ (and this is the distance between the line <em>y</em> = 8 and the curve <em>y</em> = <em>x</em> ³). Then each shell has a volume of
2<em>π</em> (9 - <em>x</em>)² (8 - <em>x</em> ³) = 2<em>π</em> (648 - 144<em>x</em> + 8<em>x</em> ² - 81<em>x</em> ³ + 18<em>x</em> ⁴ - <em>x</em> ⁵)
so that the overall volume of the solid would be

I leave the details of integrating to you.
9514 1404 393
Answer:
Ben's
Step-by-step explanation:
If E is the amount of energy that each full set of panels produces, then ...
3 of Ismael's 5 panels produce 3/5E
4 of Ben's 6 panels produce 4/6E
We can compare these fractions when they have a common denominator.
3/5E = 18/30E . . . . energy from Ismael's panels
4/6E = 20/30E . . . energy from Ben's panels
18/30 < 20/30 . . . . so Ben's panels are producing more energy
Answer:
√9 is ____rational______ number *
Step-by-step explanation:
√9 = √(3×3)=3 which is rational
Answer:
subtract -3
Step-by-step explanation:
–3 + 4x = 9
Add 3 to each side
This is the same as subtracting -3
-3 + 4x - (-3) = 9 - (-3)
4x = 9 +3
4x = 12
Answer:
3
Explanation:
3^2 is equal to 9, and 4^2 is equal to 16, so sqrt(10) must be in between 9 and 16. Since 10 is closer to 9 than to 16, sqrt(10) is closer to 3 than 4, which means that to the nearest integer sqrt(10)=3