
{{alias}}( x, y, k )
    Computes the tangent of a double-precision floating-point number on the
    interval [-π/4, π/4].

    For increased accuracy, the number for which the tangent should be evaluated
    can be supplied as a double-double number (i.e., a non-evaluated sum of two
    double-precision floating-point numbers `x` and `y`).

    The numbers `x` and `y` must satisfy `|y| < 0.5 * ulp( x )`.

    If either `x` or `y` is `NaN`, the function returns `NaN`.

    Parameters
    ----------
    x: number
        Input value (in radians).

    y: number
        Tail of `x`.

    k: integer
        If `k=1`, the function returns `tan(x+y)`. If `k=-1`, the function
        returns the negative inverse `-1/tan(x+y)`.

    Returns
    -------
    out: number
        Tangent.

    Examples
    --------
    > var out = {{alias}}( {{alias:@stdlib/constants/float64/pi}}/4.0, 0.0, 1 )
    ~1.0
    > out = {{alias}}( {{alias:@stdlib/constants/float64/pi}}/4.0, 0.0, -1 )
    ~-1.0
    > out = {{alias}}( {{alias:@stdlib/constants/float64/pi}}/6.0, 0.0, 1 )
    ~0.577
    > out = {{alias}}( 0.664, 5.288e-17, 1 )
    ~0.783

    > out = {{alias}}( NaN, 0.0, 1 )
    NaN
    > out = {{alias}}( 3.0, NaN, 1 )
    NaN
    > out = {{alias}}( 3.0, 0.0, NaN )
    NaN

    See Also
    --------

