# Revolution using disk method

1. Oct 26, 2007

### anonom30

1. The problem statement, all variables and given/known data

Compute the volume of the solid formed in the first quadrant by y=x^4 and y=125x
when rotated around the x axis.

2. Relevant equations

the integral for a disk is solved by taking the integral from a to b of pi R^2

3. The attempt at a solution

I found the integral's limits to be from 0 to 5. My problem is figuring out what to actually integrate. I have tried integrating both (x^4 - 125x)^2 and (125x - x^4)^2 with both yielding the same wrong answer. I then tried doing the integral for (125x)^2 from 0 to 5 and found that to be wrong also.

2. Oct 26, 2007