How do i calculate $lim_{hto0}frac{f(a+h^2)-f(a+h)}{h}$?












5












$begingroup$


All do i know about this problem is that f can be derived in "a".



What troubles me is the h squared,i just can't get rid of it or make it useful,no matter what i do, i always end up with it giving me an undefined limit, so it stays like that,any idea on how to get rid of it? or any rule i can use to make this easy?










share|cite|improve this question











$endgroup$

















    5












    $begingroup$


    All do i know about this problem is that f can be derived in "a".



    What troubles me is the h squared,i just can't get rid of it or make it useful,no matter what i do, i always end up with it giving me an undefined limit, so it stays like that,any idea on how to get rid of it? or any rule i can use to make this easy?










    share|cite|improve this question











    $endgroup$















      5












      5








      5


      1



      $begingroup$


      All do i know about this problem is that f can be derived in "a".



      What troubles me is the h squared,i just can't get rid of it or make it useful,no matter what i do, i always end up with it giving me an undefined limit, so it stays like that,any idea on how to get rid of it? or any rule i can use to make this easy?










      share|cite|improve this question











      $endgroup$




      All do i know about this problem is that f can be derived in "a".



      What troubles me is the h squared,i just can't get rid of it or make it useful,no matter what i do, i always end up with it giving me an undefined limit, so it stays like that,any idea on how to get rid of it? or any rule i can use to make this easy?







      calculus limits derivatives






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 31 at 21:51







      Salah Gaming

















      asked Jan 31 at 21:48









      Salah GamingSalah Gaming

      293




      293






















          3 Answers
          3






          active

          oldest

          votes


















          10












          $begingroup$

          You can write
          $$frac{f(a + h^2) - f(a+h)}{h} = h cdot frac{f(a+h^2) - f(a)}{h^2} - frac{f(a+h) - f(a)}{h}$$
          and compute these two limits individually.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            yup worked,thanks a lot!
            $endgroup$
            – Salah Gaming
            Jan 31 at 21:58



















          6












          $begingroup$

          This is
          $$lim_{hto0}frac{f(a+h^2)-f(a)}{h}-lim_{hto0}frac{f(a+h)-f(a)}{h}.$$
          If $f'(a)$ exists, this is
          $$lim_{hto0}hleft(frac{f(a+h^2)-f(a)}{h^2}right)-f'(a)=-f'(a).$$






          share|cite|improve this answer









          $endgroup$





















            3












            $begingroup$

            Hint:$$lim_{hto0}frac{f(a+h^2)-f(a)}h=lim_{hto0}hfrac{f(a+h^2)-f(a)}{h^2}=htimes f'(a)=0.$$






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              Can you explain why it would be kosher to say $lim h[K(h^2)] = lim h(lim K(w)) = lim h*f'(x) = 0$? Is it okay to split a limit that way.
              $endgroup$
              – fleablood
              Jan 31 at 21:57










            • $begingroup$
              Thanks btw u helped me a lot!
              $endgroup$
              – Salah Gaming
              Jan 31 at 21:58










            • $begingroup$
              I see you using "$fleft(a + h^2right) - fleft(aright)$" in the numerator compared to the question's "$fleft(a + h^2right) - fleft(a + hright)$" based on the value split, but you may wish to make this clear in your answer.
              $endgroup$
              – John Omielan
              Jan 31 at 22:06










            • $begingroup$
              @fleablood Yes, it is fine, as long as both limits exist.
              $endgroup$
              – José Carlos Santos
              Jan 31 at 22:10






            • 1




              $begingroup$
              No, my answer is not $0$. I did not provide an answer. I provided a hint to help the OP to obtain the answer.
              $endgroup$
              – José Carlos Santos
              Jan 31 at 22:30












            Your Answer





            StackExchange.ifUsing("editor", function () {
            return StackExchange.using("mathjaxEditing", function () {
            StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
            StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
            });
            });
            }, "mathjax-editing");

            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "69"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            autoActivateHeartbeat: false,
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            noCode: true, onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3095519%2fhow-do-i-calculate-lim-h-to0-fracfah2-fahh%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            3 Answers
            3






            active

            oldest

            votes








            3 Answers
            3






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            10












            $begingroup$

            You can write
            $$frac{f(a + h^2) - f(a+h)}{h} = h cdot frac{f(a+h^2) - f(a)}{h^2} - frac{f(a+h) - f(a)}{h}$$
            and compute these two limits individually.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              yup worked,thanks a lot!
              $endgroup$
              – Salah Gaming
              Jan 31 at 21:58
















            10












            $begingroup$

            You can write
            $$frac{f(a + h^2) - f(a+h)}{h} = h cdot frac{f(a+h^2) - f(a)}{h^2} - frac{f(a+h) - f(a)}{h}$$
            and compute these two limits individually.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              yup worked,thanks a lot!
              $endgroup$
              – Salah Gaming
              Jan 31 at 21:58














            10












            10








            10





            $begingroup$

            You can write
            $$frac{f(a + h^2) - f(a+h)}{h} = h cdot frac{f(a+h^2) - f(a)}{h^2} - frac{f(a+h) - f(a)}{h}$$
            and compute these two limits individually.






            share|cite|improve this answer









            $endgroup$



            You can write
            $$frac{f(a + h^2) - f(a+h)}{h} = h cdot frac{f(a+h^2) - f(a)}{h^2} - frac{f(a+h) - f(a)}{h}$$
            and compute these two limits individually.







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered Jan 31 at 21:52









            Umberto P.Umberto P.

            40.3k13370




            40.3k13370












            • $begingroup$
              yup worked,thanks a lot!
              $endgroup$
              – Salah Gaming
              Jan 31 at 21:58


















            • $begingroup$
              yup worked,thanks a lot!
              $endgroup$
              – Salah Gaming
              Jan 31 at 21:58
















            $begingroup$
            yup worked,thanks a lot!
            $endgroup$
            – Salah Gaming
            Jan 31 at 21:58




            $begingroup$
            yup worked,thanks a lot!
            $endgroup$
            – Salah Gaming
            Jan 31 at 21:58











            6












            $begingroup$

            This is
            $$lim_{hto0}frac{f(a+h^2)-f(a)}{h}-lim_{hto0}frac{f(a+h)-f(a)}{h}.$$
            If $f'(a)$ exists, this is
            $$lim_{hto0}hleft(frac{f(a+h^2)-f(a)}{h^2}right)-f'(a)=-f'(a).$$






            share|cite|improve this answer









            $endgroup$


















              6












              $begingroup$

              This is
              $$lim_{hto0}frac{f(a+h^2)-f(a)}{h}-lim_{hto0}frac{f(a+h)-f(a)}{h}.$$
              If $f'(a)$ exists, this is
              $$lim_{hto0}hleft(frac{f(a+h^2)-f(a)}{h^2}right)-f'(a)=-f'(a).$$






              share|cite|improve this answer









              $endgroup$
















                6












                6








                6





                $begingroup$

                This is
                $$lim_{hto0}frac{f(a+h^2)-f(a)}{h}-lim_{hto0}frac{f(a+h)-f(a)}{h}.$$
                If $f'(a)$ exists, this is
                $$lim_{hto0}hleft(frac{f(a+h^2)-f(a)}{h^2}right)-f'(a)=-f'(a).$$






                share|cite|improve this answer









                $endgroup$



                This is
                $$lim_{hto0}frac{f(a+h^2)-f(a)}{h}-lim_{hto0}frac{f(a+h)-f(a)}{h}.$$
                If $f'(a)$ exists, this is
                $$lim_{hto0}hleft(frac{f(a+h^2)-f(a)}{h^2}right)-f'(a)=-f'(a).$$







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Jan 31 at 21:52









                Lord Shark the UnknownLord Shark the Unknown

                108k1162136




                108k1162136























                    3












                    $begingroup$

                    Hint:$$lim_{hto0}frac{f(a+h^2)-f(a)}h=lim_{hto0}hfrac{f(a+h^2)-f(a)}{h^2}=htimes f'(a)=0.$$






                    share|cite|improve this answer









                    $endgroup$













                    • $begingroup$
                      Can you explain why it would be kosher to say $lim h[K(h^2)] = lim h(lim K(w)) = lim h*f'(x) = 0$? Is it okay to split a limit that way.
                      $endgroup$
                      – fleablood
                      Jan 31 at 21:57










                    • $begingroup$
                      Thanks btw u helped me a lot!
                      $endgroup$
                      – Salah Gaming
                      Jan 31 at 21:58










                    • $begingroup$
                      I see you using "$fleft(a + h^2right) - fleft(aright)$" in the numerator compared to the question's "$fleft(a + h^2right) - fleft(a + hright)$" based on the value split, but you may wish to make this clear in your answer.
                      $endgroup$
                      – John Omielan
                      Jan 31 at 22:06










                    • $begingroup$
                      @fleablood Yes, it is fine, as long as both limits exist.
                      $endgroup$
                      – José Carlos Santos
                      Jan 31 at 22:10






                    • 1




                      $begingroup$
                      No, my answer is not $0$. I did not provide an answer. I provided a hint to help the OP to obtain the answer.
                      $endgroup$
                      – José Carlos Santos
                      Jan 31 at 22:30
















                    3












                    $begingroup$

                    Hint:$$lim_{hto0}frac{f(a+h^2)-f(a)}h=lim_{hto0}hfrac{f(a+h^2)-f(a)}{h^2}=htimes f'(a)=0.$$






                    share|cite|improve this answer









                    $endgroup$













                    • $begingroup$
                      Can you explain why it would be kosher to say $lim h[K(h^2)] = lim h(lim K(w)) = lim h*f'(x) = 0$? Is it okay to split a limit that way.
                      $endgroup$
                      – fleablood
                      Jan 31 at 21:57










                    • $begingroup$
                      Thanks btw u helped me a lot!
                      $endgroup$
                      – Salah Gaming
                      Jan 31 at 21:58










                    • $begingroup$
                      I see you using "$fleft(a + h^2right) - fleft(aright)$" in the numerator compared to the question's "$fleft(a + h^2right) - fleft(a + hright)$" based on the value split, but you may wish to make this clear in your answer.
                      $endgroup$
                      – John Omielan
                      Jan 31 at 22:06










                    • $begingroup$
                      @fleablood Yes, it is fine, as long as both limits exist.
                      $endgroup$
                      – José Carlos Santos
                      Jan 31 at 22:10






                    • 1




                      $begingroup$
                      No, my answer is not $0$. I did not provide an answer. I provided a hint to help the OP to obtain the answer.
                      $endgroup$
                      – José Carlos Santos
                      Jan 31 at 22:30














                    3












                    3








                    3





                    $begingroup$

                    Hint:$$lim_{hto0}frac{f(a+h^2)-f(a)}h=lim_{hto0}hfrac{f(a+h^2)-f(a)}{h^2}=htimes f'(a)=0.$$






                    share|cite|improve this answer









                    $endgroup$



                    Hint:$$lim_{hto0}frac{f(a+h^2)-f(a)}h=lim_{hto0}hfrac{f(a+h^2)-f(a)}{h^2}=htimes f'(a)=0.$$







                    share|cite|improve this answer












                    share|cite|improve this answer



                    share|cite|improve this answer










                    answered Jan 31 at 21:52









                    José Carlos SantosJosé Carlos Santos

                    173k23133241




                    173k23133241












                    • $begingroup$
                      Can you explain why it would be kosher to say $lim h[K(h^2)] = lim h(lim K(w)) = lim h*f'(x) = 0$? Is it okay to split a limit that way.
                      $endgroup$
                      – fleablood
                      Jan 31 at 21:57










                    • $begingroup$
                      Thanks btw u helped me a lot!
                      $endgroup$
                      – Salah Gaming
                      Jan 31 at 21:58










                    • $begingroup$
                      I see you using "$fleft(a + h^2right) - fleft(aright)$" in the numerator compared to the question's "$fleft(a + h^2right) - fleft(a + hright)$" based on the value split, but you may wish to make this clear in your answer.
                      $endgroup$
                      – John Omielan
                      Jan 31 at 22:06










                    • $begingroup$
                      @fleablood Yes, it is fine, as long as both limits exist.
                      $endgroup$
                      – José Carlos Santos
                      Jan 31 at 22:10






                    • 1




                      $begingroup$
                      No, my answer is not $0$. I did not provide an answer. I provided a hint to help the OP to obtain the answer.
                      $endgroup$
                      – José Carlos Santos
                      Jan 31 at 22:30


















                    • $begingroup$
                      Can you explain why it would be kosher to say $lim h[K(h^2)] = lim h(lim K(w)) = lim h*f'(x) = 0$? Is it okay to split a limit that way.
                      $endgroup$
                      – fleablood
                      Jan 31 at 21:57










                    • $begingroup$
                      Thanks btw u helped me a lot!
                      $endgroup$
                      – Salah Gaming
                      Jan 31 at 21:58










                    • $begingroup$
                      I see you using "$fleft(a + h^2right) - fleft(aright)$" in the numerator compared to the question's "$fleft(a + h^2right) - fleft(a + hright)$" based on the value split, but you may wish to make this clear in your answer.
                      $endgroup$
                      – John Omielan
                      Jan 31 at 22:06










                    • $begingroup$
                      @fleablood Yes, it is fine, as long as both limits exist.
                      $endgroup$
                      – José Carlos Santos
                      Jan 31 at 22:10






                    • 1




                      $begingroup$
                      No, my answer is not $0$. I did not provide an answer. I provided a hint to help the OP to obtain the answer.
                      $endgroup$
                      – José Carlos Santos
                      Jan 31 at 22:30
















                    $begingroup$
                    Can you explain why it would be kosher to say $lim h[K(h^2)] = lim h(lim K(w)) = lim h*f'(x) = 0$? Is it okay to split a limit that way.
                    $endgroup$
                    – fleablood
                    Jan 31 at 21:57




                    $begingroup$
                    Can you explain why it would be kosher to say $lim h[K(h^2)] = lim h(lim K(w)) = lim h*f'(x) = 0$? Is it okay to split a limit that way.
                    $endgroup$
                    – fleablood
                    Jan 31 at 21:57












                    $begingroup$
                    Thanks btw u helped me a lot!
                    $endgroup$
                    – Salah Gaming
                    Jan 31 at 21:58




                    $begingroup$
                    Thanks btw u helped me a lot!
                    $endgroup$
                    – Salah Gaming
                    Jan 31 at 21:58












                    $begingroup$
                    I see you using "$fleft(a + h^2right) - fleft(aright)$" in the numerator compared to the question's "$fleft(a + h^2right) - fleft(a + hright)$" based on the value split, but you may wish to make this clear in your answer.
                    $endgroup$
                    – John Omielan
                    Jan 31 at 22:06




                    $begingroup$
                    I see you using "$fleft(a + h^2right) - fleft(aright)$" in the numerator compared to the question's "$fleft(a + h^2right) - fleft(a + hright)$" based on the value split, but you may wish to make this clear in your answer.
                    $endgroup$
                    – John Omielan
                    Jan 31 at 22:06












                    $begingroup$
                    @fleablood Yes, it is fine, as long as both limits exist.
                    $endgroup$
                    – José Carlos Santos
                    Jan 31 at 22:10




                    $begingroup$
                    @fleablood Yes, it is fine, as long as both limits exist.
                    $endgroup$
                    – José Carlos Santos
                    Jan 31 at 22:10




                    1




                    1




                    $begingroup$
                    No, my answer is not $0$. I did not provide an answer. I provided a hint to help the OP to obtain the answer.
                    $endgroup$
                    – José Carlos Santos
                    Jan 31 at 22:30




                    $begingroup$
                    No, my answer is not $0$. I did not provide an answer. I provided a hint to help the OP to obtain the answer.
                    $endgroup$
                    – José Carlos Santos
                    Jan 31 at 22:30


















                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Mathematics Stack Exchange!


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    Use MathJax to format equations. MathJax reference.


                    To learn more, see our tips on writing great answers.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3095519%2fhow-do-i-calculate-lim-h-to0-fracfah2-fahh%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    MongoDB - Not Authorized To Execute Command

                    in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith

                    How to fix TextFormField cause rebuild widget in Flutter