I'm working on a tricky problem. Hopefully I got it right.

If is approximated by three inscribed rectangles of equal width on the x-axis. Determine the approximation of this integral.

After I graphed it, I found that the minimum is actually at 1. So the height of the first and second rectangles is 2. Therefore, their total area: .

The third rectangle's height: .

Total area: .

Did I do it correctly? Hopefully I got this one right. Thanks everyone.