Answer
$\frac{1}{2a}e^{ax^2}+C$
Work Step by Step
$\frac{dy}{dx}=xe^{ax^2}$
$dy=xe^{ax^2}dx$
$y=\int xe^{ax^2}dx$
let $u=ax^2$
$2ax$ $dx=du$
$y=\int xe^{ax^2}dx$
$=\frac{1}{2a}\int e^udu$
$=\frac{1}{2a}e^u+C$
$=\frac{1}{2a}e^{ax^2}+C$