Complex Number as a Vector
## Definition / Concept
The complex number:
$$z=a+ib$$
can be represented by the vector:
$$\vec z=a\hat i+b\hat j$$
## Formula
$$|\vec z|=|z|=\sqrt{a^2+b^2}$$
The sum of complex numbers corresponds to vector addition:
$$z_1+z_2\leftrightarrow\vec z_1+\vec z_2$$
## Usage
- Used to connect complex-number problems with coordinate geometry and vector interpretation.