设Z=x^2lny-sin(xy),求全微分dz
问题描述:
设Z=x^2lny-sin(xy),求全微分dz
答
解
对x求偏导:2xlny-ycosxy
对y求偏导:x²/y-xcosxy
∴
dz=(2xlny-ycosxy)dx+(x²/y-xcosxy)dy