Find the centre and radius of the circle `ax^(2) + ay^(2) + 2gx + 2fy + c = 0` where `a ne 0`.

Explanation

The co-ordinates of the centre are `(-(g)/(a), -(f)/(a))` and radius `= sqrt((g^(2))/(a^(2)) + (f^(2))/(a^(2)) - ( c)/(a)) = (sqrt(g^(2) + f^(2) - ac))/(|a|)`