$$y=x^{2}-4x+3$$
$x=\sqrt{y+1}+2$
$x=-\sqrt{y+1}+2$
$x=\sqrt{y+1}+2$
$x=-\sqrt{y+1}+2\text{, }y\geq -1$
$y=\left(x-3\right)\left(x-1\right)$