NAME

exp, expm1, log, log2, log10, log1p, pow − Exponential, logarithm, and power functions

LIBRARY

Math Library (libm.a)

SYNOPSIS

#include <math.h>

double exp    (double x);
float  expf   (float  x);
double expm1  (double x);
float  expm1f (float  x);
double log    (double x);
float  logf   (float  x);
double log2   (double x);
float  log2f  (float  x);
double log10  (double x);
float  log10f (float  x);
double log1p  (double y);
float  log1pf (float  y);
double pow    (double x, double y);
float  powf   (float  x, float  y);

DESCRIPTION

exp() and expf() compute the exponential function of x, defined as e∗∗x, where e is the constant used as a base for natural logarithms. 

expm1() and expm1f() compute exp(x)-1 accurately, even for tiny x. 

log() and logf() compute the natural (base e) logarithm of x. 

log2() and log2f() compute the base 2 logarithm of x. 

log10() and log10f() compute the common (base 10) logarithm of x. 

log1p() and log1pf() compute ln(1+y) accurately, even for tiny y. 

pow() and powf() raise a floating-point base x to a floating-point exponent y. Passing a NaN input value to this routine always produces a NaN result; but for ANSI C, pow(NaN,0) = 1.  pow(x,y) is equivalent to e∗∗(y  ln(x)).