Suppose f(x, y) = xy + 4. Determine each of the following: f (5, - 2)= f ( - 2, 5) = f(0, 0)= f(-4, -2)= f (t, 3t)= fluv, u - v)=Find the indicated partial derivatives of: 2x + 5y f (x, y) = 5x + 4y fx(x, y) = fy( x, y) =Find the indicated partial derivatives of: f (x, y) = xyey of Ox of ay