Question 450238
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi
Standard Form of an Equation of a Circle is {{{(x-h)^2 + (y-k)^2 = r^2}}}
where Pt(h,k) is the center and r is the radius
x^2 + y^2 + 4x -4y- 1 = 0  |completing squares
(x+2)^2-4 +(y-2)^2-4 -1 = 0
{{{(x+2)^2 + (y-2)^2 = 9}}}