Conic Section Formula

Equation for calculate conic section is,

$r=\frac{\mathrm{l}}{\mathrm{1\; -\; e\; ·\; cos\; (\varphi )}}$

where,
r = Radius
e = Eccentricity
l = Semi-latus rectum (the perpendicular distance at a focus from the major axis to the curve)
ϕ = Angle (angular coordinate)