## anonymous 4 years ago Evaluate: integral (pi/4)S(pi/2) (-e^cotx)/(sinx)^2 dx The answer is 1-e but idk how

1. anonymous

if you are lucky this is a u-sub and you can make $u=\cot(x)$

2. anonymous

yeah that is it, since $du=-\csc^2(x)dx$ you have just what you want and you can integrate $\int e^udu$

3. anonymous

okay thank you!