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Mathematics
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   This chapter contains information about functions for performing
mathematical computations, such as trigonometric functions.  Most of
these functions have prototypes declared in the header file `math.h'.
The complex-valued functions are defined in `complex.h'.

   All mathematical functions which take a floating-point argument have
three variants, one each for `double', `float', and `long double'
arguments.  The `double' versions are mostly defined in ISO C89.  The
`float' and `long double' versions are from the numeric extensions to C
included in ISO C99.

   Which of the three versions of a function should be used depends on
the situation.  For most calculations, the `float' functions are the
fastest.  On the other hand, the `long double' functions have the
highest precision.  `double' is somewhere in between.  It is usually
wise to pick the narrowest type that can accommodate your data.  Not
all machines have a distinct `long double' type; it may be the same as
`double'.

Mathematical Constants

Precise numeric values for often-used

constants.

Trig Functions

Sine, cosine, tangent, and friends.

Inverse Trig Functions

Arcsine, arccosine, etc.

Exponents and Logarithms

Also pow and sqrt.

Hyperbolic Functions

sinh, cosh, tanh, etc.

Special Functions

Bessel, gamma, erf.

Errors in Math Functions

Known Maximum Errors in Math Functions.

Pseudo-Random Numbers

Functions for generating pseudo-random

numbers.

FP Function Optimizations

Fast code or small code.