Volume of solid from revolving region about y-axis

[Ashford]

Homework Statement

Set up a definite integral that could be evaluated to find the volume of the solid that results when the region enclosed by the curves y=(x^2)-1, x=2, and y=0 is revolved about the y-axis.
(doesn't have to be solved) I have look at my book for help and I'm stuck.

 

[ChaoticLlama]

What have you tried so far?

Please post your attempt and any rough work that pertains to this problem.

 

[Ashford]

I've graphed it, but that still doesn't get me any where I don't know which integral to set it up with.

 

[Ashford]

Ok this is what i got probably wrong. V=$$\pi$$ (integral) [x²-1] dy

with the lower limit of the integral being 0 and the top being 2

 

[Mark44]

What does the region that will be revolved around the y-axis look like? Have you drawn a sketch of the revolved solid. Are you going to use shells or disks to get the volume?

What expression represents your typical volume element?