# cmath – mathematical functions for complex numbers

This module implements a subset of the corresponding CPython module, as described below. For more information, please refer to the original CPython documentation: cmath.

The cmath module provides some basic mathematical functions for dealing with complex numbers.

## Function

### cos

cmath.cos(z)


Returns the cosine of z.

### exp

cmath.exp(z)


Returns the exponent of z.

### log

cmath.log(z)


Returns the natural logarithm of z. The branch cuts along the negative real axis.

### log10

cmath.log10(z)


Returns the base 10 logarithm of z. The branch cuts along the negative real axis.

### phase

cmath.phase(z)


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

### polar

cmath.polar(z)


Return the polar form of z as a tuple.

### rect

cmath.rect(r, phi)


Returns the complex number of the modulus r and the phase phi.

### sin

cmath.sin(z)


Returns the sine of z.

### sqrt

cmath.sqrt(z)


Returns the square root of z.

## Constants

### cmath.e

The basis of natural logarithm

### cmath.pi

Ratio of circumference to diameter