Pq = u (1) subject to the initial conditions (i) u(0,y) = y2 (ii) u(r, 3r) = 4.r Discuss uniqueness of the solution Show also that for general initial data in parametric form, r = ro(T), y = yo(7), u = uo(7), a necessary condition for a real solution of the partial differential equation (1) to exist is duo dxo dyo > 4uo dr dt dr