Question 3. (6) Use D'Alembert's method to solve Ow =Ow, 00 w(0, t) = 0=w(1, t) =0, t20 w(x,0) =3x-13 05x51 a) Determine the value of w(r, t) at the points (r, t) = (0.7, 2), (r,t) = (0.7,3.5) b) Proof that the D'Alembert solution is a classical solution, that is that it is twice continuously differentiable. cp. 2 21 2