write a solution of the initial- 4. 3. boundary value problem. 2. 1. uku for 0 < x < L,t> 0. = u(0,1) = u(L,t) = 0, u(x, 0) = x(L-x) u =4ux for 0 < x < L,t> 0, u(0,1) = u(L,t) = 0, u(x, 0) = x(L-x) u =3uxx for 0 < x < L,t> 0, u(0,1) = u(L,t) = 0. u(x, 0) = L(1-cos(2x/L)) u = uxx for 0 < x 0, ux(0,1) = u(x,t) = 0, u(x, 0) = sin(x)