NAME    [Toc]    [Back]

     atanh, atanhf -- inverse hyperbolic tangent functions

LIBRARY    [Toc]    [Back]

     Math Library (libm, -lm)

SYNOPSIS    [Toc]    [Back]

     #include <math.h>

     double
     atanh(double x);

     float
     atanhf(float x);

DESCRIPTION    [Toc]    [Back]

     The atanh() and the atanhf() functions compute the inverse hyperbolic
     tangent of the real argument x.  For a discussion of error due to roundoff,
 see math(3).

RETURN VALUES    [Toc]    [Back]

     The atanh() and the atanhf() functions return the inverse hyperbolic tangent
 of x if successful.  On the VAX and Tahoe, if the argument has absolute
 value bigger than or equal to 1, atanh() sets the global variable
     errno to EDOM and a reserved operand fault is generated.

SEE ALSO    [Toc]    [Back]

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

HISTORY    [Toc]    [Back]

     The atanh() function appeared in 4.3BSD.


FreeBSD 5.2.1			  May 6, 1991			 FreeBSD 5.2.1