# math.3erl - Man Page

Mathematical functions.

## Description

This module provides an interface to a number of mathematical functions.

Note:

Not all functions are provided on all platforms. In particular, the erf/1 and erfc/1 functions are not provided on Windows.

## Exports

`acos(X) -> float()`
`acosh(X) -> float()`
`asin(X) -> float()`
`asinh(X) -> float()`
`atan(X) -> float()`
`atan2(Y, X) -> float()`
`atanh(X) -> float()`
`ceil(X) -> float()`
`cos(X) -> float()`
`cosh(X) -> float()`
`exp(X) -> float()`
`floor(X) -> float()`
`fmod(X, Y) -> float()`
`log(X) -> float()`
`log10(X) -> float()`
`log2(X) -> float()`
`pow(X, Y) -> float()`
`sin(X) -> float()`
`sinh(X) -> float()`
`sqrt(X) -> float()`
`tan(X) -> float()`
`tanh(X) -> float()`
Types:

Y = X = number()

A collection of mathematical functions that return floats. Arguments are numbers.

`erf(X) -> float()`
Types:

X = number()

Returns the error function of X, where:

`erf(X) = 2/sqrt(pi)*integral from 0 to X of exp(-t*t) dt.`
`erfc(X) -> float()`
Types:

X = number()

erfc(X) returns 1.0 - erf(X), computed by methods that avoid cancellation for large X.

`pi() -> float()`

A useful number.

## Limitations

As these are the C library, the same limitations apply.

## Referenced By

stdlib 4.1 Ericsson AB Erlang Module Definition