Reciprocal of a Complex Number
## Formula
For:
$$z=a+ib,\qquad z\ne0$$
$$\frac1z=\frac{\bar z}{|z|^2}$$
Therefore:
$$\frac1{a+ib}=\frac{a-ib}{a^2+b^2}$$
## Conditions / Special Cases
$$z\ne0\Leftrightarrow a^2+b^2\ne0$$
## Usage
- Used to simplify reciprocal expressions and complex-number divisions.