NAME
erf, erfc - error functions

SYNOPSIS
#include <math.h>

double erf(x)
double x;

double erfc(x)
double x;

DESCRIPTION
Erf(x) returns the error function of x; where

erf(x) = 2/sqrt(pi)*integral from 0 to x of exp(-t*t) dt.

Erfc(x) returns 1.0-erf(x).

The entry for erfc is provided because of the extreme loss of
relative accuracy if erf(x) is called for large x and the result
subtracted from 1. (e.g. for x = 10, 12 places are lost).

SEE ALSO
libm(3)