$$f ( x ) = x ^ { 2 } - 3 x + 2 g ( x ) = x ^ { 2 } - 2 x + 1$$
$g=\frac{1}{2}+\frac{1}{2x}$
$x\neq 0$
$x=\frac{1}{2g-1}$
$g\neq \frac{1}{2}$
