distribution of constants over integrals












0












$begingroup$


I'm seeing this as part of a proof for the reduction formula and I see this:



enter image description here



So am I correct for saying that if you multiply the $sin^{n-2}{x}$ by $(1 - sin^2{x})$, you get $sin^{n-2}{x} - sin^n{x}$ and so the $(n-1) int sin^{n-2}{x}cdot cos^2{x}$ becomes what is shown below? is that right? Generally, $int a - b = int a - int b$ right? That integral rule is visually intuitive right?










share|cite|improve this question









$endgroup$

















    0












    $begingroup$


    I'm seeing this as part of a proof for the reduction formula and I see this:



    enter image description here



    So am I correct for saying that if you multiply the $sin^{n-2}{x}$ by $(1 - sin^2{x})$, you get $sin^{n-2}{x} - sin^n{x}$ and so the $(n-1) int sin^{n-2}{x}cdot cos^2{x}$ becomes what is shown below? is that right? Generally, $int a - b = int a - int b$ right? That integral rule is visually intuitive right?










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      I'm seeing this as part of a proof for the reduction formula and I see this:



      enter image description here



      So am I correct for saying that if you multiply the $sin^{n-2}{x}$ by $(1 - sin^2{x})$, you get $sin^{n-2}{x} - sin^n{x}$ and so the $(n-1) int sin^{n-2}{x}cdot cos^2{x}$ becomes what is shown below? is that right? Generally, $int a - b = int a - int b$ right? That integral rule is visually intuitive right?










      share|cite|improve this question









      $endgroup$




      I'm seeing this as part of a proof for the reduction formula and I see this:



      enter image description here



      So am I correct for saying that if you multiply the $sin^{n-2}{x}$ by $(1 - sin^2{x})$, you get $sin^{n-2}{x} - sin^n{x}$ and so the $(n-1) int sin^{n-2}{x}cdot cos^2{x}$ becomes what is shown below? is that right? Generally, $int a - b = int a - int b$ right? That integral rule is visually intuitive right?







      integration






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Jan 5 at 1:45









      Jwan622Jwan622

      2,34611632




      2,34611632






















          2 Answers
          2






          active

          oldest

          votes


















          2












          $begingroup$

          Assuming that all of your functions are "nice", the integral operator is linear, and will split over sums and respects multiplication by constants. Formally, we have that
          $$
          int(af(x)+bg(x)),dx = aint f(x),dx + bint g(x),dx
          $$

          for all real numbers $a$ and $b$ and all functions $f$ and $g$ which have anti-derivatives.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            How does one define 'nice'?
            $endgroup$
            – user150203
            Jan 5 at 1:57










          • $begingroup$
            @DavidG I mentioned it in the final sentence; you need to be able to find anti-derivatives for both $f$ and $g$. The issue is that the class of functions which have anti-derivatives is difficult to characterize, so most of the time we pick a criterion that is way too powerful, like $f$ and $g$ are continuous. That would be enough to know that they have anti-derivatives, but it is not a necessary property.
            $endgroup$
            – ItsJustTranscendenceBro
            Jan 5 at 1:59










          • $begingroup$
            Cheers, appreciate the detail.
            $endgroup$
            – user150203
            Jan 5 at 2:03






          • 1




            $begingroup$
            @DavidG For more information for anyone who reads this in the future (and you as well if you don't already know), you can look at this post for more info.
            $endgroup$
            – ItsJustTranscendenceBro
            Jan 5 at 2:04










          • $begingroup$
            Awesome, I will check out. Thanks again.
            $endgroup$
            – user150203
            Jan 5 at 2:10



















          1












          $begingroup$

          Yes, the fact that $int [a(x)-b(x)]dx$ is equal to $int a(x)dx-int b(x)dx$ is a well-known valid rule for manipulating integrals. This is also known as the "difference rule" for integrals. There is a good proof explaining why this rule is true on Paul's Online Notes.



          In particular, your manipulation of these integrals above seems correct.






          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: "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%2f3062323%2fdistribution-of-constants-over-integrals%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            2 Answers
            2






            active

            oldest

            votes








            2 Answers
            2






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            2












            $begingroup$

            Assuming that all of your functions are "nice", the integral operator is linear, and will split over sums and respects multiplication by constants. Formally, we have that
            $$
            int(af(x)+bg(x)),dx = aint f(x),dx + bint g(x),dx
            $$

            for all real numbers $a$ and $b$ and all functions $f$ and $g$ which have anti-derivatives.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              How does one define 'nice'?
              $endgroup$
              – user150203
              Jan 5 at 1:57










            • $begingroup$
              @DavidG I mentioned it in the final sentence; you need to be able to find anti-derivatives for both $f$ and $g$. The issue is that the class of functions which have anti-derivatives is difficult to characterize, so most of the time we pick a criterion that is way too powerful, like $f$ and $g$ are continuous. That would be enough to know that they have anti-derivatives, but it is not a necessary property.
              $endgroup$
              – ItsJustTranscendenceBro
              Jan 5 at 1:59










            • $begingroup$
              Cheers, appreciate the detail.
              $endgroup$
              – user150203
              Jan 5 at 2:03






            • 1




              $begingroup$
              @DavidG For more information for anyone who reads this in the future (and you as well if you don't already know), you can look at this post for more info.
              $endgroup$
              – ItsJustTranscendenceBro
              Jan 5 at 2:04










            • $begingroup$
              Awesome, I will check out. Thanks again.
              $endgroup$
              – user150203
              Jan 5 at 2:10
















            2












            $begingroup$

            Assuming that all of your functions are "nice", the integral operator is linear, and will split over sums and respects multiplication by constants. Formally, we have that
            $$
            int(af(x)+bg(x)),dx = aint f(x),dx + bint g(x),dx
            $$

            for all real numbers $a$ and $b$ and all functions $f$ and $g$ which have anti-derivatives.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              How does one define 'nice'?
              $endgroup$
              – user150203
              Jan 5 at 1:57










            • $begingroup$
              @DavidG I mentioned it in the final sentence; you need to be able to find anti-derivatives for both $f$ and $g$. The issue is that the class of functions which have anti-derivatives is difficult to characterize, so most of the time we pick a criterion that is way too powerful, like $f$ and $g$ are continuous. That would be enough to know that they have anti-derivatives, but it is not a necessary property.
              $endgroup$
              – ItsJustTranscendenceBro
              Jan 5 at 1:59










            • $begingroup$
              Cheers, appreciate the detail.
              $endgroup$
              – user150203
              Jan 5 at 2:03






            • 1




              $begingroup$
              @DavidG For more information for anyone who reads this in the future (and you as well if you don't already know), you can look at this post for more info.
              $endgroup$
              – ItsJustTranscendenceBro
              Jan 5 at 2:04










            • $begingroup$
              Awesome, I will check out. Thanks again.
              $endgroup$
              – user150203
              Jan 5 at 2:10














            2












            2








            2





            $begingroup$

            Assuming that all of your functions are "nice", the integral operator is linear, and will split over sums and respects multiplication by constants. Formally, we have that
            $$
            int(af(x)+bg(x)),dx = aint f(x),dx + bint g(x),dx
            $$

            for all real numbers $a$ and $b$ and all functions $f$ and $g$ which have anti-derivatives.






            share|cite|improve this answer









            $endgroup$



            Assuming that all of your functions are "nice", the integral operator is linear, and will split over sums and respects multiplication by constants. Formally, we have that
            $$
            int(af(x)+bg(x)),dx = aint f(x),dx + bint g(x),dx
            $$

            for all real numbers $a$ and $b$ and all functions $f$ and $g$ which have anti-derivatives.







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered Jan 5 at 1:51









            ItsJustTranscendenceBroItsJustTranscendenceBro

            1712




            1712












            • $begingroup$
              How does one define 'nice'?
              $endgroup$
              – user150203
              Jan 5 at 1:57










            • $begingroup$
              @DavidG I mentioned it in the final sentence; you need to be able to find anti-derivatives for both $f$ and $g$. The issue is that the class of functions which have anti-derivatives is difficult to characterize, so most of the time we pick a criterion that is way too powerful, like $f$ and $g$ are continuous. That would be enough to know that they have anti-derivatives, but it is not a necessary property.
              $endgroup$
              – ItsJustTranscendenceBro
              Jan 5 at 1:59










            • $begingroup$
              Cheers, appreciate the detail.
              $endgroup$
              – user150203
              Jan 5 at 2:03






            • 1




              $begingroup$
              @DavidG For more information for anyone who reads this in the future (and you as well if you don't already know), you can look at this post for more info.
              $endgroup$
              – ItsJustTranscendenceBro
              Jan 5 at 2:04










            • $begingroup$
              Awesome, I will check out. Thanks again.
              $endgroup$
              – user150203
              Jan 5 at 2:10


















            • $begingroup$
              How does one define 'nice'?
              $endgroup$
              – user150203
              Jan 5 at 1:57










            • $begingroup$
              @DavidG I mentioned it in the final sentence; you need to be able to find anti-derivatives for both $f$ and $g$. The issue is that the class of functions which have anti-derivatives is difficult to characterize, so most of the time we pick a criterion that is way too powerful, like $f$ and $g$ are continuous. That would be enough to know that they have anti-derivatives, but it is not a necessary property.
              $endgroup$
              – ItsJustTranscendenceBro
              Jan 5 at 1:59










            • $begingroup$
              Cheers, appreciate the detail.
              $endgroup$
              – user150203
              Jan 5 at 2:03






            • 1




              $begingroup$
              @DavidG For more information for anyone who reads this in the future (and you as well if you don't already know), you can look at this post for more info.
              $endgroup$
              – ItsJustTranscendenceBro
              Jan 5 at 2:04










            • $begingroup$
              Awesome, I will check out. Thanks again.
              $endgroup$
              – user150203
              Jan 5 at 2:10
















            $begingroup$
            How does one define 'nice'?
            $endgroup$
            – user150203
            Jan 5 at 1:57




            $begingroup$
            How does one define 'nice'?
            $endgroup$
            – user150203
            Jan 5 at 1:57












            $begingroup$
            @DavidG I mentioned it in the final sentence; you need to be able to find anti-derivatives for both $f$ and $g$. The issue is that the class of functions which have anti-derivatives is difficult to characterize, so most of the time we pick a criterion that is way too powerful, like $f$ and $g$ are continuous. That would be enough to know that they have anti-derivatives, but it is not a necessary property.
            $endgroup$
            – ItsJustTranscendenceBro
            Jan 5 at 1:59




            $begingroup$
            @DavidG I mentioned it in the final sentence; you need to be able to find anti-derivatives for both $f$ and $g$. The issue is that the class of functions which have anti-derivatives is difficult to characterize, so most of the time we pick a criterion that is way too powerful, like $f$ and $g$ are continuous. That would be enough to know that they have anti-derivatives, but it is not a necessary property.
            $endgroup$
            – ItsJustTranscendenceBro
            Jan 5 at 1:59












            $begingroup$
            Cheers, appreciate the detail.
            $endgroup$
            – user150203
            Jan 5 at 2:03




            $begingroup$
            Cheers, appreciate the detail.
            $endgroup$
            – user150203
            Jan 5 at 2:03




            1




            1




            $begingroup$
            @DavidG For more information for anyone who reads this in the future (and you as well if you don't already know), you can look at this post for more info.
            $endgroup$
            – ItsJustTranscendenceBro
            Jan 5 at 2:04




            $begingroup$
            @DavidG For more information for anyone who reads this in the future (and you as well if you don't already know), you can look at this post for more info.
            $endgroup$
            – ItsJustTranscendenceBro
            Jan 5 at 2:04












            $begingroup$
            Awesome, I will check out. Thanks again.
            $endgroup$
            – user150203
            Jan 5 at 2:10




            $begingroup$
            Awesome, I will check out. Thanks again.
            $endgroup$
            – user150203
            Jan 5 at 2:10











            1












            $begingroup$

            Yes, the fact that $int [a(x)-b(x)]dx$ is equal to $int a(x)dx-int b(x)dx$ is a well-known valid rule for manipulating integrals. This is also known as the "difference rule" for integrals. There is a good proof explaining why this rule is true on Paul's Online Notes.



            In particular, your manipulation of these integrals above seems correct.






            share|cite|improve this answer









            $endgroup$


















              1












              $begingroup$

              Yes, the fact that $int [a(x)-b(x)]dx$ is equal to $int a(x)dx-int b(x)dx$ is a well-known valid rule for manipulating integrals. This is also known as the "difference rule" for integrals. There is a good proof explaining why this rule is true on Paul's Online Notes.



              In particular, your manipulation of these integrals above seems correct.






              share|cite|improve this answer









              $endgroup$
















                1












                1








                1





                $begingroup$

                Yes, the fact that $int [a(x)-b(x)]dx$ is equal to $int a(x)dx-int b(x)dx$ is a well-known valid rule for manipulating integrals. This is also known as the "difference rule" for integrals. There is a good proof explaining why this rule is true on Paul's Online Notes.



                In particular, your manipulation of these integrals above seems correct.






                share|cite|improve this answer









                $endgroup$



                Yes, the fact that $int [a(x)-b(x)]dx$ is equal to $int a(x)dx-int b(x)dx$ is a well-known valid rule for manipulating integrals. This is also known as the "difference rule" for integrals. There is a good proof explaining why this rule is true on Paul's Online Notes.



                In particular, your manipulation of these integrals above seems correct.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Jan 5 at 1:50









                Noble MushtakNoble Mushtak

                15.3k1835




                15.3k1835






























                    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%2f3062323%2fdistribution-of-constants-over-integrals%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

                    How do I know what Microsoft account the skydrive app is syncing to?

                    When does type information flow backwards in C++?

                    Grease: Live!