Question

$f\left(x\right)=\frac{x}{x+2}$ find the range of function.

Answer 1

Let $f\left(x\right)=y$

$y=\frac{x}{x+2}2y+xy=x2y=x-xyx=\frac{2y}{1-y}$

The function is not defined when $y=1$

So the range is $y\ne 1$