## Precalculus (6th Edition) Blitzer

The rectangular equation is, $x=6$
Using, $r\cos \theta =x$ we will convert the polar equation to the rectangular equation. Therefore, \begin{align} & r=6\sec \theta \\ & r=\frac{6}{\cos \theta } \\ & r\cos \theta =6 \\ & x=6 \end{align}