Question

integral of (sinx-cosx)/√(cos^4(x) +sin^4(x))

Answer 1

Is this your function
\[
\frac{\sin (x)-\cos
(x)}{\sqrt{\sin ^4(x)+\cos
^4(x)}}
\]

Answer 2

Mathematica could not do it in a closed form. I will be interested if someone can get it.