Let $f(x)={\displaystyle \underset{0}{\overset{x}{}}}(1-t^2)e^{t^2}dt,on$ what intervals $isf$ increasing?

Hint: A function $fis$ increasing when its first derivative $is$ positive, that $is$ when $f^{\text{'}}(x)>0.$

$(1,)$

$(-,-1)$

$(-,-1)(1,)$

$(-1,1)$