I need help with Calc 2 - Volume by slicing and revolution around axis.

Answer 1

Use the below formula to find the volume. a and b represent the lower and upper limit of x. From the graph you have, find R(x) which is nothing but the (vertical) distance between the graph and the axis of rotation. For instance, if you have a graph y=x² graph and your axis of rotation is y=(-1), then R(x) would be x² minus (-1) which is x²+1. Square this value and take the integral from a to b and multiply the result with pi to get the volume. Hope this helps

Answer 2

The basic idea with rotations is that you establish the function [f(x)] as the radius of a circle, and integrate

π∫^a_b [f(x)]² dx where a = x_start and b = x_end.

What specific issues are you having?