Answer
$ x^2+y^2= 4$
Work Step by Step
The conversion of polar co-ordinates $(r, \theta)$ to rectangular coordinates $(x,y)$ can be expressed as:
$x=r \ \cos(\theta)$, $y=r \ \sin(\theta) $
where, $r=\sqrt{x^2+y^2}$
We have: $r = 2 \ ~~~(1)$
Squaring both sides of equation (1), we have:
$r^2 = 4$
Make the necessary substitutions to convert to $x,y$:
Therefore, $ x^2+y^2= 4$
