TAN                      Tangent

 y = TAN(numexpr)

    Returns the tangent of the angle whose value, in radians, is expressed
    in numexpr.

     numexpr    A numeric expression.

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      Notes:    If the argument is a double-precision expression, TAN
                returns a double-precision value. Otherwise single
                precision is returned.

                If TAN overflows, execution is halted, unless the error is
                trapped by an error-handling routine.