NAME
math — math functions and constants
DESCRIPTION
This file contains declarations of all the functions in the
Math Library (described in Section (3M)).
It also defines the following constants that may be used in
initializations or returned as error values:
- HUGE_VAL
The maximum value (type
double)
of a double-precision floating-point number (IEEE positive INFINITY).
- NAN
A quiet NaN (Not-a-Number) value (type
float).
- INFINITY
A positive infinity value (type
float).
The following mathematical constants are defined for user convenience:
- M_E
The base of natural logarithms
(e).
- M_LOG2E
The base-2 logarithm of
e.
- M_LOG10E
The base-10 logarithm of
e.
- M_LN2
The natural logarithm of 2.
- M_LN10
The natural logarithm of 10.
- M_PI
The ratio of the circumference of a circle to its diameter.
(There are also several fractions of
π,
its reciprocal, and its square root:
M_PI_2,
M_PI_4,
M_1_PI,
M_2_PI,
and
M_2_SQRTPI).
- M_SQRT2
The positive square root of 2.
- M_SQRT1_2
The positive square root of 1/2.
For the definitions of various machine-dependent constants,
see the description of the
<values.h>
header file.
STANDARDS CONFORMANCE
<math.h>: SVID3, XPG4.2, ANSI C
Printable version
