# Math Help - [SOLVED] The Disk Method, Hwk

1. ## [SOLVED] The Disk Method, Hwk

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

so i dont think this is the washer method

y = (x/5)^2

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

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
$

3. oh Okay Got it.

ans is 50pi =] thank you skeeter