求抽象函数二阶偏导

2024-11-17 14:33:13
推荐回答(1个)
回答(1):

z'x=f1+1/y*f2
z''xx=f11+1/yf12 + 1/yf21+ 1/y^2f22
=f11+2/y*f21+1/y^2f22
选D