# math

### MODULE

math

### MODULE SUMMARY

Mathematical Functions

### DESCRIPTION

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

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

### EXPORTS

`pi() -> float()`

A useful number.

`sin(X)`
`cos(X)`
`tan(X)`
`asin(X)`
`acos(X)`
`atan(X)`
`atan2(Y, X)`
`sinh(X)`
`cosh(X)`
`tanh(X)`
`asinh(X)`
`acosh(X)`
`atanh(X)`
`exp(X)`
`log(X)`
`log10(X)`
`pow(X, Y)`
`sqrt(X)`

Types:

`X = Y = number()`

A collection of math functions which 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`.

### Bugs

As these are the C library, the bugs are the same.

### AUTHORS

Mike Williams - support@erlang.ericsson.se

stdlib 1.14.3
Copyright © 1991-2007 Ericsson AB