\[Equation\] \[Graph\] \[Focus\] \[Length\space of\space LR\] \[Directrix\] \[Length\space of\space Major\space Axis\]
\[\frac{x^2}{a^2}\space+\frac{y^2}{b^2}\space=1\]
\[a>b\]
\[(±ae,0)\] \[\frac{2b^2}{a}\] \[x=±\frac{a}{e}\] \[2a\]
\[\frac{x^2}{a^2}\space+\frac{y^2}{b^2}\space=1\]
\[a < b\]
\[(0,±be)\] \[\frac{2a^2}{b}\] \[y=±\frac{b}{e}\] \[2b\]

Equations of Tangent of Ellipse

\[Equation\] \[Parametric\space Coordinates\] \[Equation\space of\space tangent\] \[Condition\space of \space Tangency\]
\[\frac{x^2}{a^2}\space+\frac{y^2}{b^2}\space=1\]
\[a>b\]
\[(acos\theta,bsin\theta)\] \[y=mx±\sqrt{am^2+b^2}\]
\[\frac{xcos\theta}{a}+\frac{ysin\theta}{b}=1\]
\[c=±\sqrt{am^2+b^2}\]
\[\frac{x^2}{a^2}\space+\frac{y^2}{b^2}\space=1\]
\[a < b\]
\[(bcos\theta,asin\theta)\] \[y=mx±\sqrt{bm^2+a^2}\]
\[\frac{xcos\theta}{b}+\frac{ysin\theta}{a}=1\]
\[c=±\sqrt{bm^2+a^2}\]

Equations of Normal of Ellipse

\[Equation\] \[Parametric\space Coordinates\] \[Equation\space of\space Normal\] \[Condition\space of \space Normality\]
\[\frac{x^2}{a^2}\space+\frac{y^2}{b^2}\space=1\]
\[a>b\]
\[(acos\theta,bsin\theta)\] \[\frac{ax}{cos\theta}-\frac{by}{sin\theta}=a^2-b^2\] \[c=±\frac{m(a^2-b^2)}{\sqrt{a^2+b^2m^2}}\]
\[\frac{x^2}{a^2}\space+\frac{y^2}{b^2}\space=1\]
\[a < b\]
\[(bcos\theta,asin\theta)\] \[\frac{bx}{cos\theta}-\frac{ay}{sin\theta}=b^2-a^2\] \[c=±\frac{m(b^2-a^2)}{\sqrt{b^2+a^2m^2}}\]

Equations of Director circle of Ellipse

\[Equation\] \[Equation\space of\space Director\space Circle\]
\[\frac{x^2}{a^2}\space+\frac{y^2}{b^2}\space=1\]
\[a>b\]
\[x^2\,+\,y^2\space=\,a^2\,+\,b^2\]
\[\frac{x^2}{a^2}\space+\frac{y^2}{b^2}\space=1\]
\[a < b\]
\[x^2\,+\,y^2\space=\,a^2\,+\,b^2\]