M_PI(3) BSD Library Functions Manual M_PI(3)NAME
constants — mathematical library constants
SYNOPSIS
#include <math.h>
DESCRIPTION
The header file math.h provides macros that define a number of useful
numerical constants.
LIST OF CONSTANTS
As required by the POSIX standard, these constants are double-precision
literals, with enough digits specified as to ensure that they are cor‐
rectly rounded in double-precision:
M_E
"Euler's constant" or e; the base of the natural logarithm.
M_LOG2E
M_LOG10E
The logarithms of e in base 2 and 10, respectively.
M_LN2
M_LN10
The natural logarithms of 2 and 10, respectively. Note that these are
the reciprocals of the preceeding two values.
M_PI
M_PI_2
M_PI_4
pi, pi/2, and pi/4, respectively.
M_1_PI
M_2_PI
1/pi and 2/pi, respectively.
M_2_SQRTPI
Two divided by the square root of pi.
M_SQRT2
M_SQRT_1_2
The square root of two and its reciprocal, respectively.
SEE ALSOmath(3), float(3),
STANDARDS
The <math.h> functions and macros conform to the ISO/IEC 9899:2011 stan‐
dard.
BSD July 6, 2010 BSD