Limits of a density functionWriting the density of a continuous random variable in terms of a...

How do you catch Smeargle in Pokemon Go?

Looking for a specific 6502 Assembler

Why does 0.-5 evaluate to -5?

Is "the fire consumed everything on its way" correct?

I have trouble understanding this fallacy: "If A, then B. Therefore if not-B, then not-A."

What is the difference between rolling more dice versus fewer dice?

What will happen if Parliament votes "no" on each of the Brexit-related votes to be held on the 12th, 13th and 14th of March?

Limits of a density function

How does one write from a minority culture? A question on cultural references

Why zero tolerance on nudity in space?

Why are all my replica super soldiers young adults or old teenagers?

How to assess the long-term stability of a college as part of a job search

How do I prevent a homebrew Grappling Hook feature from trivializing Tomb of Annihilation?

Short story where statues have their heads replaced by those of carved insect heads

Is using an 'empty' metaphor considered bad style?

Changing the laptop's CPU. Should I reinstall Linux?

Has any human ever had the choice to leave Earth permanently?

Current across a wire with zero potential difference

Why does magnet wire need to be insulated?

Is there a verb that means to inject with poison?

How do you voice extended chords?

Does diversity provide anything that meritocracy does not?

Early credit roll before the end of the film

Is there a lava-breathing lizard creature (that could be worshipped by a cult) in 5e?



Limits of a density function


Writing the density of a continuous random variable in terms of a probabilityCriteria to select the number of neighbors in the k-th-nearest-neighbor density estimationExpectation of density ratio of two iid variablesFind the mode of a probability distribution functionProbability density function of transformed variableProve f(x) is a probability density function (pdf)Interpretation of the hazard rate and the probability density functionHow can I show that Uniform($0,A$) ,as $A to infty$, is an improper denisty?Parzen density estimates convergenceSymmetric probability density function proof













2












$begingroup$


If the limit of a density function exists does it the follow that it is zero? To put is formally



$$exists a in mathbb R lim_{t rightarrow infty} f(t) = a Rightarrow a= 0.$$










share|cite|improve this question









$endgroup$

















    2












    $begingroup$


    If the limit of a density function exists does it the follow that it is zero? To put is formally



    $$exists a in mathbb R lim_{t rightarrow infty} f(t) = a Rightarrow a= 0.$$










    share|cite|improve this question









    $endgroup$















      2












      2








      2





      $begingroup$


      If the limit of a density function exists does it the follow that it is zero? To put is formally



      $$exists a in mathbb R lim_{t rightarrow infty} f(t) = a Rightarrow a= 0.$$










      share|cite|improve this question









      $endgroup$




      If the limit of a density function exists does it the follow that it is zero? To put is formally



      $$exists a in mathbb R lim_{t rightarrow infty} f(t) = a Rightarrow a= 0.$$







      pdf






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked 4 hours ago









      Jesper HybelJesper Hybel

      921614




      921614






















          1 Answer
          1






          active

          oldest

          votes


















          3












          $begingroup$

          Yes.



          Suppose the limit is anything else, so $lim_{t rightarrow infty} f(t) = a neq 0$. Then, by the definition of the limit, there is an $N$ so that for all $t > N$, $| f(t) - a | < frac{a}{2}$. In particular, $f(t) > frac{a}{2}$ in this reigon.



          But then:



          $$
          int_{mathbf{R}} f(t) dt geq int_{N}^{infty} f(t) dt geq int_{N}^{infty} frac{a}{2} dt = infty
          $$



          So $f$ cannot be a density function.






          share|cite|improve this answer











          $endgroup$













            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: "65"
            };
            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: false,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: null,
            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
            },
            onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstats.stackexchange.com%2fquestions%2f394594%2flimits-of-a-density-function%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            3












            $begingroup$

            Yes.



            Suppose the limit is anything else, so $lim_{t rightarrow infty} f(t) = a neq 0$. Then, by the definition of the limit, there is an $N$ so that for all $t > N$, $| f(t) - a | < frac{a}{2}$. In particular, $f(t) > frac{a}{2}$ in this reigon.



            But then:



            $$
            int_{mathbf{R}} f(t) dt geq int_{N}^{infty} f(t) dt geq int_{N}^{infty} frac{a}{2} dt = infty
            $$



            So $f$ cannot be a density function.






            share|cite|improve this answer











            $endgroup$


















              3












              $begingroup$

              Yes.



              Suppose the limit is anything else, so $lim_{t rightarrow infty} f(t) = a neq 0$. Then, by the definition of the limit, there is an $N$ so that for all $t > N$, $| f(t) - a | < frac{a}{2}$. In particular, $f(t) > frac{a}{2}$ in this reigon.



              But then:



              $$
              int_{mathbf{R}} f(t) dt geq int_{N}^{infty} f(t) dt geq int_{N}^{infty} frac{a}{2} dt = infty
              $$



              So $f$ cannot be a density function.






              share|cite|improve this answer











              $endgroup$
















                3












                3








                3





                $begingroup$

                Yes.



                Suppose the limit is anything else, so $lim_{t rightarrow infty} f(t) = a neq 0$. Then, by the definition of the limit, there is an $N$ so that for all $t > N$, $| f(t) - a | < frac{a}{2}$. In particular, $f(t) > frac{a}{2}$ in this reigon.



                But then:



                $$
                int_{mathbf{R}} f(t) dt geq int_{N}^{infty} f(t) dt geq int_{N}^{infty} frac{a}{2} dt = infty
                $$



                So $f$ cannot be a density function.






                share|cite|improve this answer











                $endgroup$



                Yes.



                Suppose the limit is anything else, so $lim_{t rightarrow infty} f(t) = a neq 0$. Then, by the definition of the limit, there is an $N$ so that for all $t > N$, $| f(t) - a | < frac{a}{2}$. In particular, $f(t) > frac{a}{2}$ in this reigon.



                But then:



                $$
                int_{mathbf{R}} f(t) dt geq int_{N}^{infty} f(t) dt geq int_{N}^{infty} frac{a}{2} dt = infty
                $$



                So $f$ cannot be a density function.







                share|cite|improve this answer














                share|cite|improve this answer



                share|cite|improve this answer








                edited 2 hours ago

























                answered 3 hours ago









                Matthew DruryMatthew Drury

                25.8k262104




                25.8k262104






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Cross Validated!


                    • 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%2fstats.stackexchange.com%2fquestions%2f394594%2flimits-of-a-density-function%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

                    Щит и меч (фильм) Содержание Названия серий | Сюжет |...

                    is 'sed' thread safeWhat should someone know about using Python scripts in the shell?Nexenta bash script uses...

                    Meter-Bus Содержание Параметры шины | Стандартизация |...