***AP Calculus Help!***

Test Preparation
1

<p>I'm having a hard time finding out the answer to this. I know it's 4pi/5, but I can't for the life of me figure out how. Here it is:</p>

<p>Use cylindrical shell method to find volume of solid bounded by following:</p>

<p>x=12(y^2 - y^3)</p>

<p>x=0</p>

<p>rotate around the line y=1.</p>

<p>When I rotated around y=0 (the previous problem, I got it right, the answer being 6pi/5. now, however, I'm stuck.)</p>

<p>Help Please!!!!!</p>

2

<p>nevermind, I figured it out. i took the integral of 1-(12(y^2-y^3)) and got it right.</p>

3

<p>On the subject of volumes; If you have y=1, x=ln2, and y= e^x/2, and they want you to rotate it around x = -1. Just to confirm, would the equation be: pi*fnInt( (0 + 1)^2-(lny^2+1)^2), y, 1, sqrt(2)) ? Thanks.</p>