$clambda$ is an eigenvalue of $cA$?












0












$begingroup$



"Let $A$ a square matrix have an eigenvalue $lambda$ with corresponding eigenvector $v$. Let $cin F$. Then $clambda$ is an eigenvalue of $cA$."




This is true right? since the eigenvalues of $A$ form the eigenvectors in $A$, multiplying $A$ by a scalar $c$ is still equivalent to $A$, so their eigenvalues must be proportional too?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    More concretely, simply show that there is an eigenvector of $cA$ with eigenvalue $clambda$...
    $endgroup$
    – angryavian
    Jan 21 at 1:51
















0












$begingroup$



"Let $A$ a square matrix have an eigenvalue $lambda$ with corresponding eigenvector $v$. Let $cin F$. Then $clambda$ is an eigenvalue of $cA$."




This is true right? since the eigenvalues of $A$ form the eigenvectors in $A$, multiplying $A$ by a scalar $c$ is still equivalent to $A$, so their eigenvalues must be proportional too?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    More concretely, simply show that there is an eigenvector of $cA$ with eigenvalue $clambda$...
    $endgroup$
    – angryavian
    Jan 21 at 1:51














0












0








0





$begingroup$



"Let $A$ a square matrix have an eigenvalue $lambda$ with corresponding eigenvector $v$. Let $cin F$. Then $clambda$ is an eigenvalue of $cA$."




This is true right? since the eigenvalues of $A$ form the eigenvectors in $A$, multiplying $A$ by a scalar $c$ is still equivalent to $A$, so their eigenvalues must be proportional too?










share|cite|improve this question











$endgroup$





"Let $A$ a square matrix have an eigenvalue $lambda$ with corresponding eigenvector $v$. Let $cin F$. Then $clambda$ is an eigenvalue of $cA$."




This is true right? since the eigenvalues of $A$ form the eigenvectors in $A$, multiplying $A$ by a scalar $c$ is still equivalent to $A$, so their eigenvalues must be proportional too?







linear-algebra






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 21 at 1:59









El borito

666216




666216










asked Jan 21 at 1:50









ximxim

516




516








  • 1




    $begingroup$
    More concretely, simply show that there is an eigenvector of $cA$ with eigenvalue $clambda$...
    $endgroup$
    – angryavian
    Jan 21 at 1:51














  • 1




    $begingroup$
    More concretely, simply show that there is an eigenvector of $cA$ with eigenvalue $clambda$...
    $endgroup$
    – angryavian
    Jan 21 at 1:51








1




1




$begingroup$
More concretely, simply show that there is an eigenvector of $cA$ with eigenvalue $clambda$...
$endgroup$
– angryavian
Jan 21 at 1:51




$begingroup$
More concretely, simply show that there is an eigenvector of $cA$ with eigenvalue $clambda$...
$endgroup$
– angryavian
Jan 21 at 1:51










1 Answer
1






active

oldest

votes


















3












$begingroup$

Yes, this is easy to check: we have $$(cA)v=c(Av)=c(lambda v)=(clambda)v.$$ The first equality is by definition, the second by the assumption that $v$ is an eigenvector of $A$ with eigenvalue $lambda$, and the third equality is just the basic associativity property of scalar multiplication.






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%2f3081401%2fc-lambda-is-an-eigenvalue-of-ca%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, this is easy to check: we have $$(cA)v=c(Av)=c(lambda v)=(clambda)v.$$ The first equality is by definition, the second by the assumption that $v$ is an eigenvector of $A$ with eigenvalue $lambda$, and the third equality is just the basic associativity property of scalar multiplication.






    share|cite|improve this answer









    $endgroup$


















      3












      $begingroup$

      Yes, this is easy to check: we have $$(cA)v=c(Av)=c(lambda v)=(clambda)v.$$ The first equality is by definition, the second by the assumption that $v$ is an eigenvector of $A$ with eigenvalue $lambda$, and the third equality is just the basic associativity property of scalar multiplication.






      share|cite|improve this answer









      $endgroup$
















        3












        3








        3





        $begingroup$

        Yes, this is easy to check: we have $$(cA)v=c(Av)=c(lambda v)=(clambda)v.$$ The first equality is by definition, the second by the assumption that $v$ is an eigenvector of $A$ with eigenvalue $lambda$, and the third equality is just the basic associativity property of scalar multiplication.






        share|cite|improve this answer









        $endgroup$



        Yes, this is easy to check: we have $$(cA)v=c(Av)=c(lambda v)=(clambda)v.$$ The first equality is by definition, the second by the assumption that $v$ is an eigenvector of $A$ with eigenvalue $lambda$, and the third equality is just the basic associativity property of scalar multiplication.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 21 at 1:53









        Noah SchweberNoah Schweber

        126k10151290




        126k10151290






























            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%2f3081401%2fc-lambda-is-an-eigenvalue-of-ca%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

            Npm cannot find a required file even through it is in the searched directory