Consider the flow described by the complex potential $$w = Be^{−imπ}z^{m+1}$$ where $B > 0$ and $m ∈ (0,1]$.
(i) Determine the stream function $ψ$ and the potential $φ$ in plane polar coordinates $(r,θ)$.
(ii) Determine $u_r$ and $u_θ$ in plane polar coordinates $(r,θ)$.
For (i), I got $ψ=Br^{m+1} \sin ((m+1) \theta - m \pi)$ and $φ=Br^{m+1} \cos ((m+1) \theta - m \pi)$, (is this correct?)
What exactly is $u$??????