Let $f:Xto [0,1]$ be the function defined by $f(x_i)_{ige 1}=sum _{ige 1}x_i2^{-i}$. Choose the correct...












-1












$begingroup$


Let $X={(x_i)_{ige 1}:x_iin {0,1}$ for all $ige 1}$ with the metric $d((x_i),(y_i))=sum_{ige 1}|x_i-y_i|2^{-i}.$ Let $f:Xto [0,1]$ be the function defined by $f(x_i)_{ige 1}=sum _{ige 1}x_i2^{-i}$.



Choose the correct statements from below :



$1)$$f$ is continuous



$2)$$f$ is onto



$3)$$f$ is one-one



$4)$$f$ is open



My attempt : option $1)$ is true by triangle inequality.



$2)$ is true as it is a binary representation



im confused about option 3, 4



any hints/solution



thanks u










share|cite|improve this question









$endgroup$



closed as off-topic by RRL, amWhy, Paul Frost, clathratus, Leucippus Jan 13 at 7:27


This question appears to be off-topic. The users who voted to close gave this specific reason:


  • "This question is missing context or other details: Please provide additional context, which ideally explains why the question is relevant to you and our community. Some forms of context include: background and motivation, relevant definitions, source, possible strategies, your current progress, why the question is interesting or important, etc." – RRL, amWhy, Paul Frost, clathratus, Leucippus

If this question can be reworded to fit the rules in the help center, please edit the question.





















    -1












    $begingroup$


    Let $X={(x_i)_{ige 1}:x_iin {0,1}$ for all $ige 1}$ with the metric $d((x_i),(y_i))=sum_{ige 1}|x_i-y_i|2^{-i}.$ Let $f:Xto [0,1]$ be the function defined by $f(x_i)_{ige 1}=sum _{ige 1}x_i2^{-i}$.



    Choose the correct statements from below :



    $1)$$f$ is continuous



    $2)$$f$ is onto



    $3)$$f$ is one-one



    $4)$$f$ is open



    My attempt : option $1)$ is true by triangle inequality.



    $2)$ is true as it is a binary representation



    im confused about option 3, 4



    any hints/solution



    thanks u










    share|cite|improve this question









    $endgroup$



    closed as off-topic by RRL, amWhy, Paul Frost, clathratus, Leucippus Jan 13 at 7:27


    This question appears to be off-topic. The users who voted to close gave this specific reason:


    • "This question is missing context or other details: Please provide additional context, which ideally explains why the question is relevant to you and our community. Some forms of context include: background and motivation, relevant definitions, source, possible strategies, your current progress, why the question is interesting or important, etc." – RRL, amWhy, Paul Frost, clathratus, Leucippus

    If this question can be reworded to fit the rules in the help center, please edit the question.



















      -1












      -1








      -1





      $begingroup$


      Let $X={(x_i)_{ige 1}:x_iin {0,1}$ for all $ige 1}$ with the metric $d((x_i),(y_i))=sum_{ige 1}|x_i-y_i|2^{-i}.$ Let $f:Xto [0,1]$ be the function defined by $f(x_i)_{ige 1}=sum _{ige 1}x_i2^{-i}$.



      Choose the correct statements from below :



      $1)$$f$ is continuous



      $2)$$f$ is onto



      $3)$$f$ is one-one



      $4)$$f$ is open



      My attempt : option $1)$ is true by triangle inequality.



      $2)$ is true as it is a binary representation



      im confused about option 3, 4



      any hints/solution



      thanks u










      share|cite|improve this question









      $endgroup$




      Let $X={(x_i)_{ige 1}:x_iin {0,1}$ for all $ige 1}$ with the metric $d((x_i),(y_i))=sum_{ige 1}|x_i-y_i|2^{-i}.$ Let $f:Xto [0,1]$ be the function defined by $f(x_i)_{ige 1}=sum _{ige 1}x_i2^{-i}$.



      Choose the correct statements from below :



      $1)$$f$ is continuous



      $2)$$f$ is onto



      $3)$$f$ is one-one



      $4)$$f$ is open



      My attempt : option $1)$ is true by triangle inequality.



      $2)$ is true as it is a binary representation



      im confused about option 3, 4



      any hints/solution



      thanks u







      general-topology






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Dec 20 '18 at 8:38









      jasminejasmine

      1,766417




      1,766417




      closed as off-topic by RRL, amWhy, Paul Frost, clathratus, Leucippus Jan 13 at 7:27


      This question appears to be off-topic. The users who voted to close gave this specific reason:


      • "This question is missing context or other details: Please provide additional context, which ideally explains why the question is relevant to you and our community. Some forms of context include: background and motivation, relevant definitions, source, possible strategies, your current progress, why the question is interesting or important, etc." – RRL, amWhy, Paul Frost, clathratus, Leucippus

      If this question can be reworded to fit the rules in the help center, please edit the question.







      closed as off-topic by RRL, amWhy, Paul Frost, clathratus, Leucippus Jan 13 at 7:27


      This question appears to be off-topic. The users who voted to close gave this specific reason:


      • "This question is missing context or other details: Please provide additional context, which ideally explains why the question is relevant to you and our community. Some forms of context include: background and motivation, relevant definitions, source, possible strategies, your current progress, why the question is interesting or important, etc." – RRL, amWhy, Paul Frost, clathratus, Leucippus

      If this question can be reworded to fit the rules in the help center, please edit the question.






















          1 Answer
          1






          active

          oldest

          votes


















          2












          $begingroup$

          $f(1,0,0,cdots)=f(0,1,1,cdots)$ so $f$ is not one-to one.
          ${(x_i):x_1=0}equiv {(x_i):x_1 neq 1}$ is open and its image is $[0,frac 1 2]$ which is not open. Hence $f$ is not an open map.






          share|cite|improve this answer









          $endgroup$




















            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            2












            $begingroup$

            $f(1,0,0,cdots)=f(0,1,1,cdots)$ so $f$ is not one-to one.
            ${(x_i):x_1=0}equiv {(x_i):x_1 neq 1}$ is open and its image is $[0,frac 1 2]$ which is not open. Hence $f$ is not an open map.






            share|cite|improve this answer









            $endgroup$


















              2












              $begingroup$

              $f(1,0,0,cdots)=f(0,1,1,cdots)$ so $f$ is not one-to one.
              ${(x_i):x_1=0}equiv {(x_i):x_1 neq 1}$ is open and its image is $[0,frac 1 2]$ which is not open. Hence $f$ is not an open map.






              share|cite|improve this answer









              $endgroup$
















                2












                2








                2





                $begingroup$

                $f(1,0,0,cdots)=f(0,1,1,cdots)$ so $f$ is not one-to one.
                ${(x_i):x_1=0}equiv {(x_i):x_1 neq 1}$ is open and its image is $[0,frac 1 2]$ which is not open. Hence $f$ is not an open map.






                share|cite|improve this answer









                $endgroup$



                $f(1,0,0,cdots)=f(0,1,1,cdots)$ so $f$ is not one-to one.
                ${(x_i):x_1=0}equiv {(x_i):x_1 neq 1}$ is open and its image is $[0,frac 1 2]$ which is not open. Hence $f$ is not an open map.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Dec 20 '18 at 8:57









                Kavi Rama MurthyKavi Rama Murthy

                60.5k42161




                60.5k42161















                    Popular posts from this blog

                    Mont Emei

                    Province de Neuquén

                    Soliste