EXP(3) Linux Programmer's Manual EXP(3)

log, logf, logl - natural logarithmic function

#include <math.h>

double log(double x);

float logf(float x);

long double logl(long double x);

Link with -lm.

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

The log() function can return the following errors:

The argument x is negative.
The argument x is zero. The log of zero is not defined (minus infinity).

SVID 3, POSIX, BSD 4.3, ISO 9899. The float and the long double variants are C99 requirements.

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

2002-07-27

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