Question 636875
the equation of the circle is 
{{{(x-x0)^2+(y-y0)^2=R^2}}}
Where (x0, y0) is the center, R is the radius of the circle
{{{4x^2 + 4y^2 - 9 =0}}}
{{{4x^2 + 4y^2 =9}}}divide by 4
{{{x^2 + y^2 =9/4}}}
Hence, (0,0) is the center, R=3/2 is the radius