Suppose you need to know an equation of the tangent plane to a surface S at the point P(4, 1, 4). You don't have an equation for S but you know that the curves r1(t) = 4 + 2t, 1 − t2, 4 − 5t + t2 r2(u) = 3 + u2, 2u3 − 1, 2u + 2 both lie on S. Find an equation of the tangent plant at P