# I have an error when calculating “areas under a graph”

Q: Some computer algebra systems have commands that will draw approximating rectangles and evaluate the sums of their areas, at least if Xi is a left or right endpoint (for instance in Maple use leftbox, rightbox, leftsum, and rightsum)

(a) If f(x) = 1/(x^2 + 1), 0 is less-than-or-equal-to X is less-than-or-equal-to 1, find the left and right sums for n = 10, 30, 50.

A: I knew how to do this for normal problems, but she wants us to use a calculator on here by going to Sum(seq( and typing in the equations. I do everything the way she set-up, but I receive 1 as my answer (the answer for left-sided N = 10 is suppose to be around .81).

For seq( I input EXP: 1/(x^2+1), Variable: X, Start: 0, End: .9 (for left hand limit), and Step: 10. Does anyone know where I am making my mistake? I am using a TI-84 Plus calculator.