Let f be a multivariable function defined by f(x, y) = x^3y – x^2y^2

Let f be a multivariable function defined by f(x, y) = x^3y – x^2y^2 where x and y are real numbers at the point (1,1,0) Explain how to find the equation of the tangent plane & the normal line at the chosen pointo f at your chosen point.
I have that The equation of the tangent plane is f_x (P_0)(x-x_0)+f_y(P_0)(y-y_0)+f_z(P_0)(z-z_0)=0