4. Given is the following equation: x22u+5y22ueyxu=cos(x+2y) The size of the computational domain is =x. At boundaries :u=0. a. Provide discretisation using the finite difference method for h=2hx=hy. b. Provide minimum number of grid points for which the matrix of coefficients is weakly diagonally dominant. c. Provide the Gauss-Seidel (Jacobi) algorithm (written in C language) for solution of this