# 5.1 Built-in Module `math`

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

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

`ceil` (x)
  Return the ceiling of x.

`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.

`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)`.

`modf` (x)
  Return the fractional and integer parts of x. Both results carry the sign of x.

`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:

`cmath` (Complex number versions of many of these functions.)