# Thread: Need Help Integrating This!

1. ## Need Help Integrating This!

∫(u)->(1) (y1*e^(-y1)) - (u*e^(-y1)) dy1

I forgot a lot of my calculus and appreciate anyone who can integrate this!

$\int x e^{-x}dx=\int x (-e^{-x})'=-xe^{-x}+\int e^{-x}dx=-xe^{-x}-e^{-x}+C$