calculs 3

Note: please write down the Answer by hand on paper and also write each answer with the number of the questions

18. [-/1 Points] DETAILS SCALCET9 16.1.028. Find the gradient vector field Vf of f. f ( x , y , z ) = x3 yev / z Vf ( x, y, z) = 19. [-/1 Points] DETAILS . SCALCET9 16.2.003.MI. Evaluate the line integral, where C is the given plane curve. xy# ds, C is the right half of the circle x + y = 16 oriented counterclockwise