Revision sheet · Mathematics

Conic sections

Radius of a circle from its centre and a point: $r = (x - h)^{2} + (y - k)^{2}$
Radius from the general equation of a circle: $r = g^{2} + f^{2} - c$
Latus rectum of a parabola: $L = 4 a$
Foci of an ellipse: $c = a^{2} - b^{2}$
Foci of a hyperbola: $c = a^{2} + b^{2}$
Eccentricity of an ellipse or hyperbola: $e = \frac{c}{a}$
Latus rectum of an ellipse or hyperbola: $L = \frac{2 b ^{2}}{a}$