Distance Between Two Complex Numbers
## Formula
If $z_1$ and $z_2$ represent two points in the Argand plane, then the distance between them is:
$$|z_1-z_2|$$
If:
$$z_1=x_1+iy_1,\qquad z_2=x_2+iy_2$$
then:
$$|z_1-z_2|=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$$
## Conditions / Special Cases
Distance is always non-negative:
$$|z_1-z_2|\ge0$$
The distance is zero if and only if:
$$z_1=z_2$$
## Usage
- Used in geometric interpretation and locus problems involving complex numbers.