Question 2 20 marks sin(vxy) (a) Find the domain of f (x, y) = (2 marks) x- y (b) Find the limit sin(vxy) lim (x,y)- (0,0) x - y or show that the limit does not exist. (3 marks) (c) Find the tangent plane to the graph of f(x, y) = xy + 2x + y at (0, 0, f(0, 0)). (2 marks) (d) Check the differentiability of f(x, y) = xy + 2x + y at (0, 0)