# Complex Number

A complex number is a number consisting of a real part and an imaginary part. A complex number is an element of the complex plane.

Complex number is a high school-level concept that would be first encountered in a pre-calculus course covering complex numbers. It is listed in the California State Standards for Algebra II.

### Examples

Gaussian Integer: | A Gaussian integer is a complex number a + b i, where a and b are integers and i is the imaginary unit. |

i: |
i is the symbol used to denote the principal square root of -1, also called the imaginary unit. |

### Prerequisites

Imaginary Number: | In mathematics, an imaginary number is multiple of the imaginary unit i (the square root of -1). |

Real Number: | A real number is a number corresponding to a point on the real number line. |