# 5.1 `math` -- Mathematical functions

This module is always available. It provides access to the mathematical functions defined by the C standard.

These functions cannot be used with complex numbers; use the functions of the same name from the `cmath` module if you require support for complex numbers. The distinction between functions which support complex numbers and those which don't is made since most users do not want to learn quite as much mathematics as required to understand complex numbers. Receiving an exception instead of a complex result allows earlier detection of the unexpected complex number used as a parameter, so that the programmer can determine how and why it was generated in the first place.

The following functions provided by this module:

`acos` (x)
  Return the arc cosine of x.

`asin` (x)
  Return the arc sine of x.

`atan` (x)
  Return the arc tangent of x.

`atan2` (y, x)
  Return `atan(y / x)`.

`ceil` (x)
  Return the ceiling of x as a real.

`cos` (x)
  Return the cosine of x.

`cosh` (x)
  Return the hyperbolic cosine of x.

`exp` (x)
  Return `e**x`.

`fabs` (x)
  Return the absolute value of the real x.

`floor` (x)
  Return the floor of x as a real.

`fmod` (x, y)
  Return `x % y`.

`frexp` (x)
  Return the matissa and exponent for x. The mantissa is positive.

`hypot` (x, y)
  Return the Euclidean distance, `sqrt(x*x + y*y)`.

`ldexp` (x, i)
  Return `x * (2**i)`.

`log` (x)
  Return the natural logarithm of x.

`log10` (x)
  Return the base-10 logarithm of x.

`modf` (x)
  Return the fractional and integer parts of x. Both results carry the sign of x. The integer part is returned as a real.

`pow` (x, y)
  Return `x**y`.

`sin` (x)
  Return the sine of x.

`sinh` (x)
  Return the hyperbolic sine of x.

`sqrt` (x)
  Return the square root of x.

`tan` (x)
  Return the tangent of x.

`tanh` (x)
  Return the hyperbolic tangent of x.

Note that `frexp()` and `modf()` have a different call/return pattern than their C equivalents: they take a single argument and return a pair of values, rather than returning their second return value through an `output parameter' (there is no such thing in Python).

The module also defines two mathematical constants:

`pi`
  The mathematical constant pi.

`e`
  The mathematical constant e.

See Also:

Module `cmath`:
  Complex number versions of many of these functions.