# Math Help - Solving an integral by substitution (two questions)

1. Originally Posted by angel.white
I got 74/80 = 92.5%
...
But then my instructor curved it, so the grade on the books is out of 74
Nice!

2. ## Error in limits

ebonyscythe, I think you have an error in the limits of your first integral:
$u = \cos x$, so when x=0, $u = \cos (0) = 1$, and so your first integral should be $-\int_{1}^{-1} u^2*du$, not $-\int_{0}^{-1} u^2*du$.

--Kevin C.

Page 2 of 2 First 12