Question 873666
Complete the square,
{{{y=x^2-x-23}}}
{{{y=(x^2-x+1/4)-23-1/4}}}
{{{y=(x-1/2)^2-92/4-1/4}}}
{{{y=(x-1/2)^2-93/4}}}
The vertex is (1/2,-93/4).
{{{0=(x-1/2)^2-93/4}}}
{{{(x-1/2)^2=93/4}}}
{{{x-1/2=0 +- sqrt(93)/2}}}
{{{x=1/2 +- sqrt(93)/2}}}