Question

Find the volume of the solid when rotated about the y-axis.
y=3-x^2/9
x=3
the answer is 45/2 pi
can you show me how to get that answer? thank you

Answer 1

Is that x the only thing over 9 or is it the whole expression over 9?

Answer 2

you are posting this again

Answer 3

yea i dont get it still

Answer 4

its only x^2 that is over 9

Answer 5

Was it answered already @aajugdar ?

Answer 6

ok.

Answer 7

well

Answer 8

you got the points
find equation with x^2
integrate it from 0 to 3

Answer 9

ok x^2= 9y-27 but when i integrate it im not getting the right answer

Answer 10

let me see

Answer 11

Your 9y-27 is not correct.

Answer 12

it should be 27-9y

Answer 13

\[\int\limits_{3}^{0}\]isnt that the same thing

Answer 14

@electrokid

Answer 15

I am getting 81 pi /2

Answer 16

That's the answer I got.

Answer 17

am i doing this right? \[\int\limits_{3}^{0} \pi(27-9y)^2 - \pi(3)^2 \]

Answer 18

(162-81)/2*pi

Answer 19

I can't read that, my laptop is currently processing mass at 0% so I can't read anything from the equation editor...and is being snarky!

Answer 20

math*

Answer 21

hang on...trying the other method.

Answer 22

ok

Answer 23

Does that say
\[y=3-\frac{1}{9}x^2?\]

Answer 24

ya