1. intergration help please

$\int$(-infty.to.infinty) $xe^{-x^2}$

2. Originally Posted by Legendsn3verdie

$\int_{-\infty}^{\infty} xe^{-x^2} \, dx$
First, I fixed the latex and added the dx.

$x e^{-x^2}$ is an odd function so $\int_{-a}^{a} xe^{-x^2} \, dx = 0$. Therefore ......

(Note: Following on from ....... will give you the Cauchy Principle Value).