---
title: "cmath"
aliases:
    - firmwareapi/micropython/cmath.html
    - firmwareapi/micropython/cmath.md
    - chapter/firmwareapi/micropython/cmath
---

The `cmath` module provides some basic mathematical functions for working with complex numbers. Floating point support required for this module.

## Methods

#### cmath.cos(z)

Return the cosine of `z`.

#### cmath.exp(z)

Return the exponential of `z`.

#### cmath.log(z)

Return the natural logarithm of `z`. The branch cut is along the negative real axis.

#### cmath.log10(z)

Return the base-10 logarithm of `z`. The branch cut is along the negative real axis.

#### cmath.phase(z)

Returns the phase of the number `z`, in the range (-pi, +pi).

#### cmath.polar(z)

Returns, as a tuple, the polar form of `z`.

#### cmath.rect(r, phi)

Returns the complex number with modulus `r` and phase `phi`.

#### cmath.sin(z)

Return the sine of `z`.

#### cmath.sqrt(z)

Return the square-root of `z`.

## Constants

* `cmath.e`: Base of the natural logarithm
* `cmath.pi`: The ratio of a circle's circumference to its diameter