Circle with Centre other than (0,0) (Leaving Cert Mathematics): Flashcards

Set of all points equidistant from a fixed centre

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

Centre of the circle

Radius of the circle

Coordinates of any point on the circle

$x^2+y^2-2hx-2ky+h^2+k^2-r^2=0$

Substitute coordinates into equation and check if true

Fixed distance from centre to any point on circle

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

Verify points on circle; solve line-circle intersections