Answer
The rectangular equation is ${{x}^{2}}+{{y}^{2}}=x$.
Work Step by Step
Using ${{r}^{2}}={{x}^{2}}+{{y}^{2}}$ we will convert the polar equation to the rectangular equation.
$x=r\cos \theta,y=r\sin \theta $
Therefore,
$\begin{align}
& r=\cos \theta \\
& {{r}^{2}}=r\cos \theta \\
& {{x}^{2}}+{{y}^{2}}=r\cos \theta \\
& =x
\end{align}$
