4. [-/4 Points] DETAILS SCALCET9 14.1.057. MY NOTES ASK YOUR TEACHER Graph the function using various domains and viewpoints. If your software also produces level curves, then plot some contour lines of the same function and compare with the graph. (Select Update Graph to see your response plotted on the screen. Select the Submit button to grade your response.) z = f(x, y) = f(x, y) = xy - x3 (monkey saddle) (Write an equation for the cross section at z = -1 using x and y.) (Write an equation for the cross section at z = 0 using x and y.) (Write an equation for the cross section at z = 1 using x and y.)