log1p
EXPM1(3)                   Linux Programmer's Manual                  EXPM1(3)
NAME
       expm1, log1p - exponential minus 1, logarithm of 1 plus argument
SYNOPSIS
       #include <math.h>
       double expm1(double x);
       double log1p(double x);
DESCRIPTION
       expm1(x) returns a value equivalent to `exp (x) - 1'. It is computed in
       a way that is accurate even if the value of  x  is  near  zero--a  case
       where  `exp (x) - 1' would be inaccurate due to subtraction of two num-
       bers that are nearly equal.
       log1p(x) returns a value equivalent to `log (1 + x)'. It is computed in
       a way that is accurate even if the value of x is near zero.
CONFORMING TO
       BSD
SEE ALSO
       exp(3), log(3)
GNU                               1995-09-16                          EXPM1(3)