1. Tetration (hyper-exponentiation)


    From course of mathematics the principle of a construction of operations of "multiplication" and "exponentation" is known:

,

. (1.1)

    In 1987 considered properties of operation "tetration" mentioned in the popular scientific literature (originally in my publications the name "superdegree") appears:

, (1.2)

where tetration number (label of the author).

    Numerically at whole it is easy to check up, that the given operation is noncommutative:

.

    Therefore, there are completely various two inverses of operations designated so:

, .

    The datas of a label are taken by analogy to the radical and log:

and .

    Originally was decided to try to receive an assotiation for a numerical evaluation of the superradical of positive whole tetrations. The given task can be decided, determining a tetration through a degree and to take advantage of one of methods of a numerical solution of the equation , for example of half division. The task of deriving of the formula of an evaluation of the superradical posed.

    Some thousands of years back were open the iterative formula for an evaluation of a square root:

, (1.3)

where some initial approximation of a square root from .

    Criterion of reaching of the given exactitude is the condition:

,

where , value on of iteration.

    There was is offered a hypothesis about existence of the similar iterative formula for the superradical of the second tetration:

(1.4)

    The given assotiation was obtained by logic reasonings:

  1. .
  2. From the previous item and (1.3) it is necessary instead of to apply .
  3. In the formula (1.3) is applied average arithmetical and . As the expression was transformed in , was decided to try to change a rank of operations on the average arithmetical, i.e. to replace it on average geometric and .

    The obtained iterative formula (1.4) has appeared a converging sequence at . (In the following paragraphs another will be reduced fast converging an iterative sequence for values of argument ).

    The autumn of 1987 undertook attempt to consider values of function at (set of integers), in particular . Was decided to accept from (1.2) . Then to that is equal ? From the definition (1.1) it is possible to notice, that , i.e. (a set of natural numbers). The given definition can be expanded for etc.:

. (1.5)

    Similarly from (1.2) is obtained, at :

(1.6)

    Values of expressions (1.5) and (1.6) at :

, , .

    From expression (1.6) it is easy to receive a value of a tetration at negative tetrations. For example, at :

,

,

.

    Problem: " to that is equal , at ? "

 

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