# Thread: Finding volume using integrals: base x^2 + y^2 = 4, cross-sections perp to x-axis are

1. ## Finding volume using integrals: base x^2 + y^2 = 4, cross-sections perp to x-axis are

Hi all! I hope all is well. I am struggling with this problem:

The base of a solid is the unit circle x^2 + y^2 = 4, and its cross-sections perpendicular to the x-axis are rectangles of height 10. Find its volume.

I know I need take the integral of the area of the rectangle, so I what I did was A=lw, A=10*sqroot(x^2-4), but when I integrate that it doesn't work out! Any help would be appreciated! Thanks!

2. Originally Posted by lifelonglearner26
Hi all! I hope all is well. I am struggling with this problem:

The base of a solid is the unit circle x^2 + y^2 = 4, and its cross-sections perpendicular to the x-axis are rectangles of height 10. Find its volume.

I know I need take the integral of the area of the rectangle, so I what I did was A=lw, A=10*sqroot(x^2-4), but when I integrate that it doesn't work out! Any help would be appreciated! Thanks!
Exactly what did you integrate and how. Include limits of integration.