log

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Version: 2002-07-27 (mandriva - 22/10/07)

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Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

log, logf, logl - natural logarithmic function

SYNOPSIS

 #include <math.h>
 
 double log(double x);
 

 float logf(float x);
 

 long double logl(long double x);

Link with -lm.

DESCRIPTION

The log() function returns the natural logarithm of x.

ERRORS

The log() function can return the following errors:
EDOM
The argument x is negative.
ERANGE
The argument x is zero. The log of zero is not defined (minus infinity).

CONFORMING TO

SVr4, 4.3BSD, C89. The float and long double variants are C99 requirements.

SEE ALSO

cbrt(3), clog(3), log1p(3), sqrt(3)