Equation of a Circle (Leaving Cert Mathematics): Quizzes

Points at a fixed distance from a point

$x^2 + y^2 = r^2$

$7$

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

$(x - 3)^2 + (y + 4)^2 = 25$

$(2, -5)$

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

$(-g, -f)$

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

$g = -3$, $f = 4$, $c = 9$

$4$

Tangents, chords, or intersections