Circle Equation

$(x - a)^2 +(y - b)^2 = r^2$

$(a, b)$ is the centre of the circle. $(x, y)$ is the current position. $r$ is the radius of the circle.

Example: Finding the equation of a circle

Given: centre position, point

Info
TODO

Example: Factionalising

x^{2} + y^{2} - 14 x + 16 y - 12 = 0 x^{2} - 14 x + y^{2} + 16 y = 12 (x - 7)^{2} - 49 + (y + 8)^{2} - 64 = 12 (x - 7)^{2} + (y + 8)^{2} = 125 (radius)^{2}

Note: Uses Completing The Square to factorise.