Volume of Solid using cross sections

[BigJon]

Homework Statement

Find the volume of a solid whose base bounded by y=x+1 and y=x^2-1, with cross section of a square perpendicular to x-axis

The Attempt at a Solution

So i set up the problem like this delta volume= y^2*delta x, that being the area of the square where i get loss is that I am supposed to subtract the curves from one another but don't know if its setup like this:

integral from -1 to 2 ((x+1)-(x^2-1))^2 dx or ((x+1)^2)-((x^2-1)^2) dx, from here i know how to do the rest

 

[Dick]

What do you think the length of the side of the square is for a given value of x? Then what would be the area of that square?

 

[BigJon]

Haha thanx, now that you put it that way :)