The function (x,y) is differentiable and u=x2y,v=x2+y. Use the chain rule to write the partial derivatives x and y in terms of u and u. Hence show that if obeys the partial differential equation x+2xy=0 this can be written as v=0 (assuming that x=0 ). Hence write down the general solution of the partial differential equation, expressing the answer in terms of x and y and an arbitrary function