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

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

$(-g, -f)$

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

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

Radius is zero; circle reduces to a point

Equation does not represent a real circle

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

Circle's centre and radius

Complete the square for $x$ and $y$ terms

Finding centre and radius from $g$, $f$, $c$

standard form