# [SOLVED] The Disk Method, Hwk

• June 24th 2009, 06:15 PM
XplicitZero
[SOLVED] The Disk Method, Hwk
Consider the solid obtained by rotating the region bounded by the given curves about the y-axis.

http://www.webassign.net/www23/symIm...febc2462ba.gif

so i dont think this is the washer method

y = (x/5)^2
• June 24th 2009, 06:24 PM
skeeter
Quote:

Originally Posted by XplicitZero
Consider the solid obtained by rotating the region bounded by the given curves about the y-axis.

http://www.webassign.net/www23/symIm...febc2462ba.gif

Okay, so i think this is the washer method( where the inside is empty)

so its " Pi ( outer radius)^2 - Pi ( Inner radius)^2 "

Can someone please explain to me how i can find both the radii

disk method ...

$V = \pi \int_0^2 (5\sqrt{y})^2 \, dy
$
• June 24th 2009, 06:36 PM
XplicitZero
oh Okay Got it.

ans is 50pi =] thank you skeeter