Are polynomial functions with fractional exponents transcendental?

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I'm having trouble categorizing fractional--order systems, that means functions like



$$ f(x) = K cdot (1 + sqrtx)$$



or more generally, e.g.



$$ g(x) = dfraca_0 + a_1 x^1/2 + a_2 x^1 + a_3 x^3/2b_0 + b_1 x^1/2 + b_2 x^1 + b_3 x^3/2$$



where the exponents are rational numbers $gamma in mathbbQ$. All coefficients and $K$ are real numbers. $x$ is, in my case, complex.



I doubt they can still be refered as rational functions, can they? But on the other hand, are these functions transcendental functions?



The definition on Wikipedia is not entirely clear to me on that matter:




A transcendental function is an analytic function that does not satisfy a polynomial equation, in contrast to an algebraic function.1[2] In other words, a transcendental function "transcends" algebra in that it cannot be expressed in terms of a finite sequence of the algebraic operations of addition, multiplication, and root extraction.





Would the definition change, if we include real exponents $gamma in mathbbR$?



And what happens in case of the implicit form:



$$ h(x) = K cdot sqrt1 + x$$



I'm a little confused about all these definitions and I hope you can shed some light on my problem.







share|cite|improve this question

























    up vote
    0
    down vote

    favorite












    I'm having trouble categorizing fractional--order systems, that means functions like



    $$ f(x) = K cdot (1 + sqrtx)$$



    or more generally, e.g.



    $$ g(x) = dfraca_0 + a_1 x^1/2 + a_2 x^1 + a_3 x^3/2b_0 + b_1 x^1/2 + b_2 x^1 + b_3 x^3/2$$



    where the exponents are rational numbers $gamma in mathbbQ$. All coefficients and $K$ are real numbers. $x$ is, in my case, complex.



    I doubt they can still be refered as rational functions, can they? But on the other hand, are these functions transcendental functions?



    The definition on Wikipedia is not entirely clear to me on that matter:




    A transcendental function is an analytic function that does not satisfy a polynomial equation, in contrast to an algebraic function.1[2] In other words, a transcendental function "transcends" algebra in that it cannot be expressed in terms of a finite sequence of the algebraic operations of addition, multiplication, and root extraction.





    Would the definition change, if we include real exponents $gamma in mathbbR$?



    And what happens in case of the implicit form:



    $$ h(x) = K cdot sqrt1 + x$$



    I'm a little confused about all these definitions and I hope you can shed some light on my problem.







    share|cite|improve this question























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      I'm having trouble categorizing fractional--order systems, that means functions like



      $$ f(x) = K cdot (1 + sqrtx)$$



      or more generally, e.g.



      $$ g(x) = dfraca_0 + a_1 x^1/2 + a_2 x^1 + a_3 x^3/2b_0 + b_1 x^1/2 + b_2 x^1 + b_3 x^3/2$$



      where the exponents are rational numbers $gamma in mathbbQ$. All coefficients and $K$ are real numbers. $x$ is, in my case, complex.



      I doubt they can still be refered as rational functions, can they? But on the other hand, are these functions transcendental functions?



      The definition on Wikipedia is not entirely clear to me on that matter:




      A transcendental function is an analytic function that does not satisfy a polynomial equation, in contrast to an algebraic function.1[2] In other words, a transcendental function "transcends" algebra in that it cannot be expressed in terms of a finite sequence of the algebraic operations of addition, multiplication, and root extraction.





      Would the definition change, if we include real exponents $gamma in mathbbR$?



      And what happens in case of the implicit form:



      $$ h(x) = K cdot sqrt1 + x$$



      I'm a little confused about all these definitions and I hope you can shed some light on my problem.







      share|cite|improve this question













      I'm having trouble categorizing fractional--order systems, that means functions like



      $$ f(x) = K cdot (1 + sqrtx)$$



      or more generally, e.g.



      $$ g(x) = dfraca_0 + a_1 x^1/2 + a_2 x^1 + a_3 x^3/2b_0 + b_1 x^1/2 + b_2 x^1 + b_3 x^3/2$$



      where the exponents are rational numbers $gamma in mathbbQ$. All coefficients and $K$ are real numbers. $x$ is, in my case, complex.



      I doubt they can still be refered as rational functions, can they? But on the other hand, are these functions transcendental functions?



      The definition on Wikipedia is not entirely clear to me on that matter:




      A transcendental function is an analytic function that does not satisfy a polynomial equation, in contrast to an algebraic function.1[2] In other words, a transcendental function "transcends" algebra in that it cannot be expressed in terms of a finite sequence of the algebraic operations of addition, multiplication, and root extraction.





      Would the definition change, if we include real exponents $gamma in mathbbR$?



      And what happens in case of the implicit form:



      $$ h(x) = K cdot sqrt1 + x$$



      I'm a little confused about all these definitions and I hope you can shed some light on my problem.









      share|cite|improve this question












      share|cite|improve this question




      share|cite|improve this question








      edited Jul 16 at 9:13
























      asked Jul 16 at 8:51









      thewaywewalk

      183211




      183211




















          2 Answers
          2






          active

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          up vote
          1
          down vote



          accepted










          $$f(x)=1+sqrt x$$ is algebraic because it satisfies the polynomial equation



          $$(f(x)-1)^2-x=0.$$



          Same goes with your function $g(x)$, though the polynomial will be of a much higher degree.



          Transcendence begins with irrational exponents, as they would require a polynomial of infinite degree.






          share|cite|improve this answer




























            up vote
            2
            down vote













            The confusion arises because it is quite unclear in which ring the coefficients of the polynomial are supposed to be. The notion of algebraicity can only be defined properly if it is clear what is meant by a polynomial equation. Visiting the French article on the same subject, we see that the coefficients are supposed to be polynomials over the ground field, which in this case are the complex numbers.



            Based on that definition, I would say that the first function is indeed algebraic, because it satisfies a quadratic equation, as is easily seen. (Given that $K$ denotes a constant.)



            The second function should also be algebraic, because one may use polynomials to counteract growing exponents in the denominator. (I don't see the equation immediately.)






            share|cite|improve this answer





















            • In general, transcendental means precisely "not algebraic". Once one settles for a polynomial ring, the definitions become clear.
              – AlgebraicsAnonymous
              Jul 16 at 9:10






            • 1




              I gave some more information about the other variables.
              – thewaywewalk
              Jul 16 at 9:11











            Your Answer




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            2 Answers
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            active

            oldest

            votes








            2 Answers
            2






            active

            oldest

            votes









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            active

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            up vote
            1
            down vote



            accepted










            $$f(x)=1+sqrt x$$ is algebraic because it satisfies the polynomial equation



            $$(f(x)-1)^2-x=0.$$



            Same goes with your function $g(x)$, though the polynomial will be of a much higher degree.



            Transcendence begins with irrational exponents, as they would require a polynomial of infinite degree.






            share|cite|improve this answer

























              up vote
              1
              down vote



              accepted










              $$f(x)=1+sqrt x$$ is algebraic because it satisfies the polynomial equation



              $$(f(x)-1)^2-x=0.$$



              Same goes with your function $g(x)$, though the polynomial will be of a much higher degree.



              Transcendence begins with irrational exponents, as they would require a polynomial of infinite degree.






              share|cite|improve this answer























                up vote
                1
                down vote



                accepted







                up vote
                1
                down vote



                accepted






                $$f(x)=1+sqrt x$$ is algebraic because it satisfies the polynomial equation



                $$(f(x)-1)^2-x=0.$$



                Same goes with your function $g(x)$, though the polynomial will be of a much higher degree.



                Transcendence begins with irrational exponents, as they would require a polynomial of infinite degree.






                share|cite|improve this answer













                $$f(x)=1+sqrt x$$ is algebraic because it satisfies the polynomial equation



                $$(f(x)-1)^2-x=0.$$



                Same goes with your function $g(x)$, though the polynomial will be of a much higher degree.



                Transcendence begins with irrational exponents, as they would require a polynomial of infinite degree.







                share|cite|improve this answer













                share|cite|improve this answer



                share|cite|improve this answer











                answered Jul 16 at 9:17









                Yves Daoust

                111k665204




                111k665204




















                    up vote
                    2
                    down vote













                    The confusion arises because it is quite unclear in which ring the coefficients of the polynomial are supposed to be. The notion of algebraicity can only be defined properly if it is clear what is meant by a polynomial equation. Visiting the French article on the same subject, we see that the coefficients are supposed to be polynomials over the ground field, which in this case are the complex numbers.



                    Based on that definition, I would say that the first function is indeed algebraic, because it satisfies a quadratic equation, as is easily seen. (Given that $K$ denotes a constant.)



                    The second function should also be algebraic, because one may use polynomials to counteract growing exponents in the denominator. (I don't see the equation immediately.)






                    share|cite|improve this answer





















                    • In general, transcendental means precisely "not algebraic". Once one settles for a polynomial ring, the definitions become clear.
                      – AlgebraicsAnonymous
                      Jul 16 at 9:10






                    • 1




                      I gave some more information about the other variables.
                      – thewaywewalk
                      Jul 16 at 9:11















                    up vote
                    2
                    down vote













                    The confusion arises because it is quite unclear in which ring the coefficients of the polynomial are supposed to be. The notion of algebraicity can only be defined properly if it is clear what is meant by a polynomial equation. Visiting the French article on the same subject, we see that the coefficients are supposed to be polynomials over the ground field, which in this case are the complex numbers.



                    Based on that definition, I would say that the first function is indeed algebraic, because it satisfies a quadratic equation, as is easily seen. (Given that $K$ denotes a constant.)



                    The second function should also be algebraic, because one may use polynomials to counteract growing exponents in the denominator. (I don't see the equation immediately.)






                    share|cite|improve this answer





















                    • In general, transcendental means precisely "not algebraic". Once one settles for a polynomial ring, the definitions become clear.
                      – AlgebraicsAnonymous
                      Jul 16 at 9:10






                    • 1




                      I gave some more information about the other variables.
                      – thewaywewalk
                      Jul 16 at 9:11













                    up vote
                    2
                    down vote










                    up vote
                    2
                    down vote









                    The confusion arises because it is quite unclear in which ring the coefficients of the polynomial are supposed to be. The notion of algebraicity can only be defined properly if it is clear what is meant by a polynomial equation. Visiting the French article on the same subject, we see that the coefficients are supposed to be polynomials over the ground field, which in this case are the complex numbers.



                    Based on that definition, I would say that the first function is indeed algebraic, because it satisfies a quadratic equation, as is easily seen. (Given that $K$ denotes a constant.)



                    The second function should also be algebraic, because one may use polynomials to counteract growing exponents in the denominator. (I don't see the equation immediately.)






                    share|cite|improve this answer













                    The confusion arises because it is quite unclear in which ring the coefficients of the polynomial are supposed to be. The notion of algebraicity can only be defined properly if it is clear what is meant by a polynomial equation. Visiting the French article on the same subject, we see that the coefficients are supposed to be polynomials over the ground field, which in this case are the complex numbers.



                    Based on that definition, I would say that the first function is indeed algebraic, because it satisfies a quadratic equation, as is easily seen. (Given that $K$ denotes a constant.)



                    The second function should also be algebraic, because one may use polynomials to counteract growing exponents in the denominator. (I don't see the equation immediately.)







                    share|cite|improve this answer













                    share|cite|improve this answer



                    share|cite|improve this answer











                    answered Jul 16 at 9:08









                    AlgebraicsAnonymous

                    69111




                    69111











                    • In general, transcendental means precisely "not algebraic". Once one settles for a polynomial ring, the definitions become clear.
                      – AlgebraicsAnonymous
                      Jul 16 at 9:10






                    • 1




                      I gave some more information about the other variables.
                      – thewaywewalk
                      Jul 16 at 9:11

















                    • In general, transcendental means precisely "not algebraic". Once one settles for a polynomial ring, the definitions become clear.
                      – AlgebraicsAnonymous
                      Jul 16 at 9:10






                    • 1




                      I gave some more information about the other variables.
                      – thewaywewalk
                      Jul 16 at 9:11
















                    In general, transcendental means precisely "not algebraic". Once one settles for a polynomial ring, the definitions become clear.
                    – AlgebraicsAnonymous
                    Jul 16 at 9:10




                    In general, transcendental means precisely "not algebraic". Once one settles for a polynomial ring, the definitions become clear.
                    – AlgebraicsAnonymous
                    Jul 16 at 9:10




                    1




                    1




                    I gave some more information about the other variables.
                    – thewaywewalk
                    Jul 16 at 9:11





                    I gave some more information about the other variables.
                    – thewaywewalk
                    Jul 16 at 9:11













                     

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