Q32 Suppose the point P = (Co, yo, Zo) lies on the graph z = f(x, y). a Give the formula for tangent plane to this graph at P. b z = f(x, y) is a level surface of F(x, y, z) = f(x, y) - 2. Use the gradient of F to write the equation of the tangent plane to F(x, y, z) = 0 at P. C Are these equations equivalent? Justify your answer with algebra.Q34 Suppose f(x, y) is a differentiable function and Vf(a, b) is not the zero vector. How many unit vectors u exist such that Daf(a, b) = 0. How are they related geometrically