The stream function for flow in a \(90^{\circ}\) corner is:

\[\psi=\frac{r v_{o}}{\pi^{2}-4}\left(2 \pi \theta \sin \theta+4 \theta \cos \theta-\pi^{2} \sin \theta\right)\]

a. What are the velocity components?

b. Calculate the vorticity for this two-dimensional flow. Plot lines of constant vorticity.