题目
4.设u(x,y)=f(e^x)·g(sin y)，其中f(x),g(x)均有连续导数，则(partial^2u)/(partial xpartial y)=（）.A. e^xsin yf'(e^x)g'(sin y)B. ue^xcos yf'(e^x)g'(sin y)C. e^xcos yf'(e^x)g'(sin y)D. ue^xsin yf'(e^x)g'(sin y)
4.设u(x,y)=f(e^{x})·g(sin y)，其中f(x),g(x)均有连续导数，则$\frac{\partial^{2}u}{\partial x\partial y}=$（）.
A. $e^{x}sin yf'(e^{x})g'(sin y)$
B. $ue^{x}cos yf'(e^{x})g'(sin y)$
C. $e^{x}cos yf'(e^{x})g'(sin y)$
D. $ue^{x}sin yf'(e^{x})g'(sin y)$
题目解答
答案
C. $e^{x}cos yf'(e^{x})g'(sin y)$