\begin{definition}[Definition:Polar of Point/Ellipse]
Let $\EE$ be an ellipse embedded in a Cartesian plane in reduced form with the equation:
:$\dfrac {x^2} {a^2} + \dfrac {y^2} {b^2} = 1$
Let $P = \tuple {x_0, y_0}$ be an arbitrary point in the Cartesian plane.
The '''polar of $P$ with respect to $\EE$''' is the straight line whose equation is given by:
:$\dfrac {x x_0} {a^2} + \dfrac {y y_0} {b^2} = 1$
\end{definition}