LOG(3) Linux Programmers Manual LOG(3)
log, logf, logl - natural logarithmic function
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.
EDOM The argument x is negative.
ERANGE The argument x is zero. The log of zero is not defined (minus
SVr4, 4.3BSD, C89. The float and long double variants are C99 require
cbrt(3), clog(3), log1p(3), sqrt(3)
This page is part of release 3.05 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.