NAME

     erf, erfc - error function and complementary error function

SYNOPSIS

     #include <math.h>

     double erf(double x);

     double erfc (double x);

DESCRIPTION

     The erf() function returns the error function of x;  defined
     as

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

     The erfc() function returns the complementary error function
     of x, that is 1.0 - erf(x).

CONFORMING TO

     SVID 3, BSD 4.3

SEE ALSO

     exp(3)