Question

Найдите производную y=ln(x+y)

Answer 1

$y=ln(x+y)$
$y'=frac{1}{x+y}*(x+y)'=frac{1}{x+y}*(1+y')$
$y'(x+y)=1+y'$
$y'(x+y-1)=1$
$y'=frac{1}{x+y-1}$