$Ω$ is simply connected in $C$, $u$ is a harmonic function in $Ω$ , $v$ in $Ω$
$$v(x,y) = \int_0^1 (yu{\Tiny x} (sx,sy)-xu{\Tiny y} (sx,sy)) ds$$
Prove that there exists a holomorphic function $u+iv$ in $Ω$
I know the Cauchy–Riemann equations and what is the result of having a harmonic function (Im not able to write with Latex, otherwise i would write it down) I tried to figure out something with this, but im not coming ahead.