PrepZii

formula

Intercepts and Parametric Equation

For $x^2+y^2+2gx+2fy+c=0$ , the source gives axis intercepts and circle parametrisation.

\text{x-axis intercept}=2\sqrt{g^2-c}

\text{y-axis intercept}=2\sqrt{f^2-c}

x=h+r\cos\theta,\quad y=k+r\sin\theta

$\theta$

angle or parameter depending on context