The function $f$ is given by $f(x)=x^4+x^2-2.$ On which of the following intervals is $f$ increasing?

$($A$)(-\frac{1}{\sqrt[\phantom{2}]{2}},)$

$($B$)(-\frac{1}{\sqrt[\phantom{2}]{2}},\frac{1}{\sqrt[\phantom{2}]{2}})$

$($C$)(0,)$

$($D$)(-,0)$

$($E$)(-,-\frac{1}{\sqrt[\phantom{2}]{2}})$