function
<cmath> <ctgmath>

atanh

     double atanh  (double x);
      float atanhf (float x);
long double atanhl (long double x);

     double atanh (double x);
      float atanh (float x);
long double atanh (long double x);
     double asinh (T x);           // additional overloads for integral types
Compute area hyperbolic tangent
Returns the area hyperbolic tangent of x.

The area hyperbolic tangent is the inverse operation of the hyperbolic tangent.

Header <tgmath.h> provides a type-generic macro version of this function.
Additional overloads are provided in this header (<cmath>) for the integral types: These overloads effectively cast x to a double before calculations (defined for T being any integral type).

This function is also overloaded in <complex> (see complex atanh).

Parameters

x
Value whose area hyperbolic tangent is computed, in the interval [-1,+1].
If the argument is out of this interval, a domain error occurs.
For values of -1 and +1, a pole error may occur.

Return Value

Area hyperbolic tangent of x.

If a domain error occurs:
- And math_errhandling has MATH_ERRNO set: the global variable errno is set to EDOM.
- And math_errhandling has MATH_ERREXCEPT set: FE_INVALID is raised.

If a pole error occurs:
- And math_errhandling has MATH_ERRNO set: the global variable errno is set to ERANGE.
- And math_errhandling has MATH_ERREXCEPT set: FE_DIVBYZERO is raised.

Example

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/* atanh example */
#include <stdio.h>      /* printf */
#include <math.h>       /* tanh, atanh */

int main ()
{
  double param, result;
  param = tanh(1);
  result = atanh(param) ;
  printf ("The area hyperbolic tangent of %f is %f.\n", param, result);
  return 0;
}


Output:

The area hyperbolic tangent of 0.761594 is 1.000000.

See also

tanh
Compute hyperbolic tangent (function )
asinh
Compute area hyperbolic sine (function )
acosh
Compute area hyperbolic cosine (function )

C++