NEED AN URGENT SOLUTION:
For the function f(x, y) = {(xy(x^2 - y^2))/(x^2 + y^2), if (x, y) ≠ (0, 0), (0, if (x, y) = (0, 0))}:
i. Show that f_x(x, 0) = x and f_y(0, y) = -y.
ii. Show that f_xy(0, 0) ≠ f_yx(0, 0).
For the function f(x, y) = y^2, if (x, y) = (0, 0):
i. Show that f_xx,0 = x and f_y0,y = y.
ii. Show that f_xy(0, 0) ≠ f_y(0, 0).