With respect to parameters $a$ and $b$ decide, whether the 1-differential form is closed or exact.If so, find the primitive function $f(xy),\omega=df$
$ \omega = (y- \frac{a}{2}x^{2a-1}\sin(2by))dx + bx^{2a}\sin^2(by)dy=\omega_1dx+\omega_2 dy $
I dont really know how to get into this. I am really thankful for any hint on how to solve this.