Polar Form of Complex Number/Examples/2 + i

Example of Polar Form of Complex Number
The complex number $2 + i$ can be expressed as a complex number in polar form as $\polar {\sqrt 5, \arctan {\dfrac 1 2} }$.

Proof
Then:

Hence:
 * $\map \arg {2 + i} = \arctan {\dfrac 1 2}$

and hence the result.