4) Using help, identify the command vertcat and create a random matrix (size: 5, 5) with integers and find A = [magic(4) B] where B = [0,4, 1, 2]'. a) Find A(B) b) Ifc = [1 4; 3 9], find A(c) c) If d = diag([t], -2) and t=1:2:6; find d. d) Explain the output T = vertcat(A, d)