偏导数f(x,y)=ln(x+y/2x),求fx(a,b)

Question

偏导数f(x,y)=ln(x+y/2x),求fx(a,b)

Answer 1

这个不叫偏导数,叫二元函数,fx才叫对x的偏导数
fx(x,y)=1/(x+y/2x)*(-y/2x^2)=-y/(x*(x+y))
=>fx(a,b)=-b/(a*(a+b))