tanh() computes the hyperbolic tangent of x.

    tanh(x) is defined as (exp(x)-exp(-x))/(exp(x) + exp(-x)).

                           Entry-Point Names

    Generic                               Compaq
    Function   Data Type   OpenVMS        Tru64 UNIX
    Name       Required    Alpha          Alpha

    tanh       S_FLOAT     math$tanh_s    tanhf
               T_FLOAT     math$tanh_t    tanh
               X_FLOAT     math$tanh_x    tanhl
               F_FLOAT     math$tanh_f
               G_FLOAT     math$tanh_g