Consider the steady state temperature problem over the disk of radius 3 centered at the origin. ▼²u(r, 0) = 0 subject to the following boundary condition: u(3,0) = f(0) = 4 sin³ (0) + 4 cos³ (0) (a) Find u(r, 0). Please go straight to the final formula for u(r, 0); do not show the separation of variables process. You need to show all details of integration or superposition (if it applies) for credit. (b) Approximate numerically u(3/2,π/4).