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LOG(3)		       FreeBSD Library Functions Manual			LOG(3)

NAME
     log, logf,	logl, log10, log10f, log10l, log2, log2f, log2l, log1p,
     log1pf, log1pl -- logarithm functions

LIBRARY
     Math Library (libm, -lm)

SYNOPSIS
     #include <math.h>

     double
     log(double	x);

     float
     logf(float	x);

     long double
     logl(long double x);

     double
     log10(double x);

     float
     log10f(float x);

     long double
     log10l(long double	x);

     double
     log2(double x);

     float
     log2f(float x);

     long double
     log2l(long	double x);

     double
     log1p(double x);

     float
     log1pf(float x);

     long double
     log1pl(long double	x);

DESCRIPTION
     The log(),	logf(),	and logl() functions compute the natural logarithm of
     x.

     The log10(), log10f(), and	log10l() functions compute the logarithm base
     10	of x, while log2(), log2f(), and log2l() compute the logarithm base 2
     of	x.

     The log1p(), log1pf(), and	log1pl() functions compute the natural loga-
     rithm of 1	+ x.  Computing	the natural logarithm as log1p(x) is more
     accurate than computing it	as log(1 + x) when x is	close to zero.

RETURN VALUES
     These functions return the	requested logarithm; the logarithm of 1	is +0.
     An	attempt	to take	the logarithm of +-0 results in	a divide-by-zero
     exception,	and -infinity is returned.  Otherwise, attempting to take the
     logarithm of a negative number results in an invalid exception and	a
     return value of NaN.

SEE ALSO
     exp(3), ilogb(3), math(3),	pow(3)

STANDARDS
     The log(),	logf(),	logl(),	log10(), log10f(), log10l(), log2(), log2f(),
     log2l(), log1p(), log1pf(), and log1pl() functions	conform	to ISO/IEC
     9899:1999 (``ISO C99'').

FreeBSD	11.2			 June 3, 2013			  FreeBSD 11.2

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO | STANDARDS

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