Find the steady state temperature in the plate in Prob. 21 with the upper and lower sides perfectly insulated, the left side kept at 0°C, and the right side kept at f(y)°C.

Data from Prob. 21

The faces of the thin square plate in Fig. 297 with side α = 24 are perfectly insulated. The upper side is kept at 25°C and the other sides are kept at 0°C. Find the steady-state temperature u(x, y) in the plate.