Find the isotherms for the square and grid in Prob. 13 if u = sin1/4 x on

Find the isotherms for the square and grid in Prob. 13 if u = sin1/4 πx on the horizontal and -sin1/4πy on the vertical edges. Try to sketch some isotherms.

Data from Prob. 13

For the square 0 ≤ x ≤ 4, 0 ≤ y ≤ 4 let the boundary temperatures be on the horizontal and 50°C on the vertical edges. Find the temperatures at the interior points of a square grid with h = 1.