求方程xy+lny-lnx=0所确定得隐函数y=f(x)的导数dy/dx
问题描述:
求方程xy+lny-lnx=0所确定得隐函数y=f(x)的导数dy/dx
答
左右两边对x求导得y+x*y'+1/y*y'-1/x=0
则y'=(1/x-y)/(x+1/y)
即dy/dx=(1/x-y)/(x+1/y)