If z = x2 - xy + 3y" and (x, y) changes from (3, -1) to ( calculate z and dz. Odz = 1. 73 4z = 1. 7189 Odz = 0. 73 4z = 0. 7189 O dz = - 0.73 Az = - 0. 7189 Odz = - 1. 73 Az = - 1. 7189Use the chain rule to find the dz/dt. z = sin (x) cos (y , x = Vt, y = 2 O dz 2 sin (x ) sin(y) + cos(x ) cos(y) dt t2 2vt O dz 2 sin (x) sin(y) cos(x ) cos(y) dt 2vt t2 O dz Z sin(a ) cos(y) + sin( a ) costy) dt 2vt t2 O dz 2 sin (x) cos(y) sin(x) cos(y) dt t2 2vtFind the directional derivative of the function at the given point in the direction of V. f(:12, y) = 7e$sin(y) , ( ,g) , v = O 28+21\\/ 10 Q 2821\\/ 10 Q 28+21\\/ 10 O 2821 10