試題詳解

6. Note that z = f(x,y) where f is differentiable, x = g(t), and y = h(t). It is known that g(3)=2,g'(3)=5,h(3)=7,h'(3)=4,f_x(2,7)=6,and fy(2,7)=-8. Determine the value of dz/dt at t = 3.
(A)62
(B) 30
(C)32
(D)-2
(E)1。