题目
设u=f(z), z=g(xy, x^2+y^2), 其中f(z)可导, g(u, v)有连续偏导数, 则(partial u)/(partial x)= ()A. yg_1' + 2xg_2'B. f' cdot (2yg_1' + xg_2')C. 2yg_1' + xg_2'D. f' cdot (yg_1' + 2xg_2')
设$u=f(z)$, $z=g(xy, x^2+y^2)$, 其中$f(z)$可导, $g(u, v)$有连续偏导数, 则$\frac{\partial u}{\partial x}=$ ()
A. $yg_1' + 2xg_2'$
B. $f' \cdot (2yg_1' + xg_2')$
C. $2yg_1' + xg_2'$
D. $f' \cdot (yg_1' + 2xg_2')$
题目解答
答案
D. $f' \cdot (yg_1' + 2xg_2')$