TANH (The GNU Fortran Compiler)

### 8.281 `TANH` — Hyperbolic tangent function ¶

Synopsis:

  `X = TANH(X)`

Description:

  `TANH(X)` computes the hyperbolic tangent of X.

Class:

  Elemental function

Arguments:

  X | The type shall be `REAL` or `COMPLEX`.

Return value:

  The return value has same type and kind as X. If X is complex, the imaginary part of the result is in radians. If X is `REAL`, the return value lies in the range - 1 \leq tanh(x) \leq 1 .

Example:

      program test_tanh
        real(8) :: x = 2.1_8
        x = tanh(x)
      end program test_tanh

Specific names:

  Name | Argument | Return type | Standard
  --- | --- | --- | ---
  `TANH(X)` | `REAL(4) X` | `REAL(4)` | Fortran 77 and later
  `DTANH(X)` | `REAL(8) X` | `REAL(8)` | Fortran 77 and later

Standard:

  Fortran 77 and later, for a complex argument Fortran 2008 or later

See also:

  `ATANH` — Inverse hyperbolic tangent function