Problems in g, f and c (Leaving Cert Mathematics): Quizzes

$x^2 + y^2 + 2gx + 2fy + c = 0$

$(-g, -f)$

$r = \sqrt{g^2 + f^2 - c}$

$g = -2$

$f = 3$

$(2, -3)$

$5$

The radius is zero; circle reduces to point

Equation does not represent a real circle

$g^2 + f^2 - c > 0$

$(x - h)^2 + (y - k)^2 = r^2$

$(x + 4)^2 - 16$