# The axis of the parabola $y^{2}-2y+8x-23=0$ is

$\begin{array}{1 1}(1)y=-1&(2)x=-3\\(3)x=3&(4)y=1\end{array}$

$y^2-2y+8x-23=0$
$(y-1)^2-1^2 =-8x+23$
$(y-1)^2=-8x+24$
$(y-1)^2=-8(x-3)$
Put $X=x-3$ and $Y=y-1$
The equation becomes
$Y^2=-8x$
Equation of the axis is $Y=0$
ie $y-1=0$
Hence 4 is the correct answer.