EXERCISE 8.5

EXERCISE . . If w x y x y , ,  , find the linear approximation for w at ( , . Let z x y x y x y , ,  . Find the linear approximation for z at ( , . If v x y x y R , , , find the differential dv . Fig. . Linear Approximation by Tangent Plane and - - Fig. . W x t y t ( ( ), ( )) dW dt ∂ W ∂ x dt ∂ W ∂ y dt dt dt ∂ W ∂ x ∂ W ∂ y . Let V x y z yz zx x y z ( , , ) , , , ∈  . Find the differential dV .