## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$(2, \dfrac{\pi}{2} )$
The conversion of rectangular coordinates $(x,y)$ to polar coordinates $(r, \phi)$ can be computed as: $r=\sqrt{x^2+x^2}$ and $\theta=\tan^{-1}(\dfrac{y}{x})$ We have: $r=\sqrt{0^2+2^2}=\sqrt 4=2$ and $\theta=\tan^{-1}\left(\dfrac{2}{0}\right)=\dfrac{\pi}{2}$ Therefore, the point $(x,y)$ has coordinates $(2, \dfrac{\pi}{2} )$ in the polar coordinate system.