Question 74046
{{{x^2+y^2-x+2y-3=0}}}
{{{x^2-x+y^2+2y=3}}}
{{{x^2-x+1/4+y^2+2y+1=3+1/4+1}}}
{{{(x-1/2)^2+(y+1)^2=(17/4)^2}}}
So you are right the center is (0.5,-1) with a radius of {{{sqrt(17)/2}}}