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ATANH(3)                 BSD Library Functions Manual                 ATANH(3)

NAME
     atanh -- inverse hyperbolic tangent function

SYNOPSIS
     #include <math.h>

     double
     atanh(double x);

     long double
     atanhl(long double x);

     float
     atanhf(float x);

DESCRIPTION
     The atanh() function computes the inverse hyperbolic tangent of the real argument x.

SPECIAL VALUES
     atanh(+-0) returns +-0.

     atanh(+-1) returns +-infinity and raises the "divide-by-zero" floating-point exception.

     atanh(x) returns a NaN and raises the "invalid" floating-point exception for |x| > 1.

SEE ALSO
     acosh(3), asinh(3), exp(3), math(3)

STANDARDS
     The atanh() function conforms to ISO/IEC 9899:1999(E).

4.3 Berkeley Distribution      November 20, 2002     4.3 Berkeley Distribution