Why is a matrix multiplied by an eigenvector not parallel to that eigenvector?Eigenvalue and Eigenvector for the change of Basis MatrixUnder what conditions does a complex matrix with a real eigenvalue have a corresponding real eigenvector?An eigenvector is a non-zero vector such that…Proof that eigenvector corresponding to simple eigenvalue is continuousPlease help with the rank-1 matrix eigenvectoreigenvector equivalence for subspace of matrix?If every non-zero vectors be the eigenvector of a real matrix $A$, prove that $A$ is the scalar matrix $lambda I_n$.Finding a vector that is not an eigenvector of a matrixEigenvector and adjoint eigenvector not orthogonalProve that any non zero linear combination of two eigenvectors is also an eigenvector

Calculus II Professor will not accept my correct integral evaluation that uses a different method, should I bring this up further?

How to generate globally unique ids for different tables of the same database?

Welcoming 2019 Pi day: How to draw the letter π?

It's a yearly task, alright

Is a lawful good "antagonist" effective?

Why is "das Weib" grammatically neuter?

RegionDifference for Cylinder and Cuboid

Ban on all campaign finance?

Why do Australian milk farmers need to protest supermarkets' milk price?

I need to drive a 7/16" nut but am unsure how to use the socket I bought for my screwdriver

Why would a flight no longer considered airworthy be redirected like this?

Is having access to past exams cheating and, if yes, could it be proven just by a good grade?

Science-fiction short story where space navy wanted hospital ships and settlers had guns mounted everywhere

Does this AnyDice function accurately calculate the number of ogres you make unconcious with three 4th-level castings of Sleep?

How to deal with a cynical class?

Meaning of "SEVERA INDEOVI VAS" from 3rd Century slab

Russian cases: A few examples, I'm really confused

How do anti-virus programs start at Windows boot?

PTIJ: Who should pay for Uber rides: the child or the parent?

Does splitting a potentially monolithic application into several smaller ones help prevent bugs?

Professor being mistaken for a grad student

Dot in front of file

Should we release the security issues we found in our product as CVE or we can just update those on weekly release notes?

Validating user input



Why is a matrix multiplied by an eigenvector not parallel to that eigenvector?


Eigenvalue and Eigenvector for the change of Basis MatrixUnder what conditions does a complex matrix with a real eigenvalue have a corresponding real eigenvector?An eigenvector is a non-zero vector such that…Proof that eigenvector corresponding to simple eigenvalue is continuousPlease help with the rank-1 matrix eigenvectoreigenvector equivalence for subspace of matrix?If every non-zero vectors be the eigenvector of a real matrix $A$, prove that $A$ is the scalar matrix $lambda I_n$.Finding a vector that is not an eigenvector of a matrixEigenvector and adjoint eigenvector not orthogonalProve that any non zero linear combination of two eigenvectors is also an eigenvector













0












$begingroup$


If $lambda$ is a non-zero eigenvalue with a corresponding eigenvector $v$, then $A v$ is parallel to $v$.



This statement is false. Why is that? Would it be parallel to $lambda v$?










share|cite|improve this question











$endgroup$







  • 2




    $begingroup$
    What is your definition of parallel?
    $endgroup$
    – Brian Fitzpatrick
    Mar 11 at 2:23






  • 1




    $begingroup$
    What are your definitions of eigenvector and eigenvalue?
    $endgroup$
    – Brian Borchers
    Mar 11 at 2:27










  • $begingroup$
    If $vecvin S_lambda$ $Avecvcdotvecv=lambdavecvcdotvecv=lambda||vecv||^2=1 iff ||vecv||^2=dfrac1lambda$
    $endgroup$
    – Sebastian Cor
    Mar 11 at 3:05






  • 2




    $begingroup$
    What makes you think the statement is false, Samurai? Can you show us a counterexample?
    $endgroup$
    – Gerry Myerson
    Mar 11 at 4:05






  • 2




    $begingroup$
    The only explantions that I can come up with are: (1) it's a calculation mistake, (2) perhaps $lambda=0$ and in someone's definition, two vectors are said to be parallel only if they are scalar multiples of each other (this is just a wild guess; personally, I treat $0$ as a vector that is parallel to every vector).
    $endgroup$
    – user1551
    Mar 11 at 8:55
















0












$begingroup$


If $lambda$ is a non-zero eigenvalue with a corresponding eigenvector $v$, then $A v$ is parallel to $v$.



This statement is false. Why is that? Would it be parallel to $lambda v$?










share|cite|improve this question











$endgroup$







  • 2




    $begingroup$
    What is your definition of parallel?
    $endgroup$
    – Brian Fitzpatrick
    Mar 11 at 2:23






  • 1




    $begingroup$
    What are your definitions of eigenvector and eigenvalue?
    $endgroup$
    – Brian Borchers
    Mar 11 at 2:27










  • $begingroup$
    If $vecvin S_lambda$ $Avecvcdotvecv=lambdavecvcdotvecv=lambda||vecv||^2=1 iff ||vecv||^2=dfrac1lambda$
    $endgroup$
    – Sebastian Cor
    Mar 11 at 3:05






  • 2




    $begingroup$
    What makes you think the statement is false, Samurai? Can you show us a counterexample?
    $endgroup$
    – Gerry Myerson
    Mar 11 at 4:05






  • 2




    $begingroup$
    The only explantions that I can come up with are: (1) it's a calculation mistake, (2) perhaps $lambda=0$ and in someone's definition, two vectors are said to be parallel only if they are scalar multiples of each other (this is just a wild guess; personally, I treat $0$ as a vector that is parallel to every vector).
    $endgroup$
    – user1551
    Mar 11 at 8:55














0












0








0





$begingroup$


If $lambda$ is a non-zero eigenvalue with a corresponding eigenvector $v$, then $A v$ is parallel to $v$.



This statement is false. Why is that? Would it be parallel to $lambda v$?










share|cite|improve this question











$endgroup$




If $lambda$ is a non-zero eigenvalue with a corresponding eigenvector $v$, then $A v$ is parallel to $v$.



This statement is false. Why is that? Would it be parallel to $lambda v$?







linear-algebra eigenfunctions






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Mar 11 at 8:51









Rodrigo de Azevedo

13k41960




13k41960










asked Mar 11 at 2:20









Samurai BaleSamurai Bale

645




645







  • 2




    $begingroup$
    What is your definition of parallel?
    $endgroup$
    – Brian Fitzpatrick
    Mar 11 at 2:23






  • 1




    $begingroup$
    What are your definitions of eigenvector and eigenvalue?
    $endgroup$
    – Brian Borchers
    Mar 11 at 2:27










  • $begingroup$
    If $vecvin S_lambda$ $Avecvcdotvecv=lambdavecvcdotvecv=lambda||vecv||^2=1 iff ||vecv||^2=dfrac1lambda$
    $endgroup$
    – Sebastian Cor
    Mar 11 at 3:05






  • 2




    $begingroup$
    What makes you think the statement is false, Samurai? Can you show us a counterexample?
    $endgroup$
    – Gerry Myerson
    Mar 11 at 4:05






  • 2




    $begingroup$
    The only explantions that I can come up with are: (1) it's a calculation mistake, (2) perhaps $lambda=0$ and in someone's definition, two vectors are said to be parallel only if they are scalar multiples of each other (this is just a wild guess; personally, I treat $0$ as a vector that is parallel to every vector).
    $endgroup$
    – user1551
    Mar 11 at 8:55













  • 2




    $begingroup$
    What is your definition of parallel?
    $endgroup$
    – Brian Fitzpatrick
    Mar 11 at 2:23






  • 1




    $begingroup$
    What are your definitions of eigenvector and eigenvalue?
    $endgroup$
    – Brian Borchers
    Mar 11 at 2:27










  • $begingroup$
    If $vecvin S_lambda$ $Avecvcdotvecv=lambdavecvcdotvecv=lambda||vecv||^2=1 iff ||vecv||^2=dfrac1lambda$
    $endgroup$
    – Sebastian Cor
    Mar 11 at 3:05






  • 2




    $begingroup$
    What makes you think the statement is false, Samurai? Can you show us a counterexample?
    $endgroup$
    – Gerry Myerson
    Mar 11 at 4:05






  • 2




    $begingroup$
    The only explantions that I can come up with are: (1) it's a calculation mistake, (2) perhaps $lambda=0$ and in someone's definition, two vectors are said to be parallel only if they are scalar multiples of each other (this is just a wild guess; personally, I treat $0$ as a vector that is parallel to every vector).
    $endgroup$
    – user1551
    Mar 11 at 8:55








2




2




$begingroup$
What is your definition of parallel?
$endgroup$
– Brian Fitzpatrick
Mar 11 at 2:23




$begingroup$
What is your definition of parallel?
$endgroup$
– Brian Fitzpatrick
Mar 11 at 2:23




1




1




$begingroup$
What are your definitions of eigenvector and eigenvalue?
$endgroup$
– Brian Borchers
Mar 11 at 2:27




$begingroup$
What are your definitions of eigenvector and eigenvalue?
$endgroup$
– Brian Borchers
Mar 11 at 2:27












$begingroup$
If $vecvin S_lambda$ $Avecvcdotvecv=lambdavecvcdotvecv=lambda||vecv||^2=1 iff ||vecv||^2=dfrac1lambda$
$endgroup$
– Sebastian Cor
Mar 11 at 3:05




$begingroup$
If $vecvin S_lambda$ $Avecvcdotvecv=lambdavecvcdotvecv=lambda||vecv||^2=1 iff ||vecv||^2=dfrac1lambda$
$endgroup$
– Sebastian Cor
Mar 11 at 3:05




2




2




$begingroup$
What makes you think the statement is false, Samurai? Can you show us a counterexample?
$endgroup$
– Gerry Myerson
Mar 11 at 4:05




$begingroup$
What makes you think the statement is false, Samurai? Can you show us a counterexample?
$endgroup$
– Gerry Myerson
Mar 11 at 4:05




2




2




$begingroup$
The only explantions that I can come up with are: (1) it's a calculation mistake, (2) perhaps $lambda=0$ and in someone's definition, two vectors are said to be parallel only if they are scalar multiples of each other (this is just a wild guess; personally, I treat $0$ as a vector that is parallel to every vector).
$endgroup$
– user1551
Mar 11 at 8:55





$begingroup$
The only explantions that I can come up with are: (1) it's a calculation mistake, (2) perhaps $lambda=0$ and in someone's definition, two vectors are said to be parallel only if they are scalar multiples of each other (this is just a wild guess; personally, I treat $0$ as a vector that is parallel to every vector).
$endgroup$
– user1551
Mar 11 at 8:55











1 Answer
1






active

oldest

votes


















1












$begingroup$

It's hard to know what to make of your question as you didn't specify what matrix $vecv$ is an eigenvector of.
If $A$ were the matrix corresponding to that eigenvector, then $Avecv=lambdavecv$, by definition, meaning the statement would be true. Since you're sure the statement is false, then we can assume that $A$ is not the matrix corresponding to that eigenvector. In that case, of course, $Avecv$ need not equal $lambda vecv$.
If you're confused about what it means to be parallel or what an Eigenvector is, I recommend 3b1b's video on the topic.






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%2f3143196%2fwhy-is-a-matrix-multiplied-by-an-eigenvector-not-parallel-to-that-eigenvector%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









    1












    $begingroup$

    It's hard to know what to make of your question as you didn't specify what matrix $vecv$ is an eigenvector of.
    If $A$ were the matrix corresponding to that eigenvector, then $Avecv=lambdavecv$, by definition, meaning the statement would be true. Since you're sure the statement is false, then we can assume that $A$ is not the matrix corresponding to that eigenvector. In that case, of course, $Avecv$ need not equal $lambda vecv$.
    If you're confused about what it means to be parallel or what an Eigenvector is, I recommend 3b1b's video on the topic.






    share|cite|improve this answer









    $endgroup$

















      1












      $begingroup$

      It's hard to know what to make of your question as you didn't specify what matrix $vecv$ is an eigenvector of.
      If $A$ were the matrix corresponding to that eigenvector, then $Avecv=lambdavecv$, by definition, meaning the statement would be true. Since you're sure the statement is false, then we can assume that $A$ is not the matrix corresponding to that eigenvector. In that case, of course, $Avecv$ need not equal $lambda vecv$.
      If you're confused about what it means to be parallel or what an Eigenvector is, I recommend 3b1b's video on the topic.






      share|cite|improve this answer









      $endgroup$















        1












        1








        1





        $begingroup$

        It's hard to know what to make of your question as you didn't specify what matrix $vecv$ is an eigenvector of.
        If $A$ were the matrix corresponding to that eigenvector, then $Avecv=lambdavecv$, by definition, meaning the statement would be true. Since you're sure the statement is false, then we can assume that $A$ is not the matrix corresponding to that eigenvector. In that case, of course, $Avecv$ need not equal $lambda vecv$.
        If you're confused about what it means to be parallel or what an Eigenvector is, I recommend 3b1b's video on the topic.






        share|cite|improve this answer









        $endgroup$



        It's hard to know what to make of your question as you didn't specify what matrix $vecv$ is an eigenvector of.
        If $A$ were the matrix corresponding to that eigenvector, then $Avecv=lambdavecv$, by definition, meaning the statement would be true. Since you're sure the statement is false, then we can assume that $A$ is not the matrix corresponding to that eigenvector. In that case, of course, $Avecv$ need not equal $lambda vecv$.
        If you're confused about what it means to be parallel or what an Eigenvector is, I recommend 3b1b's video on the topic.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Mar 11 at 8:45









        PatrickPatrick

        1018




        1018



























            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%2f3143196%2fwhy-is-a-matrix-multiplied-by-an-eigenvector-not-parallel-to-that-eigenvector%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 should I support this large drywall patch? Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern) Announcing the arrival of Valued Associate #679: Cesar Manara Unicorn Meta Zoo #1: Why another podcast?How do I cover large gaps in drywall?How do I keep drywall around a patch from crumbling?Can I glue a second layer of drywall?How to patch long strip on drywall?Large drywall patch: how to avoid bulging seams?Drywall Mesh Patch vs. Bulge? To remove or not to remove?How to fix this drywall job?Prep drywall before backsplashWhat's the best way to fix this horrible drywall patch job?Drywall patching using 3M Patch Plus Primer

            random experiment with two different functions on unit interval Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern)Random variable and probability space notionsRandom Walk with EdgesFinding functions where the increase over a random interval is Poisson distributedNumber of days until dayCan an observed event in fact be of zero probability?Unit random processmodels of coins and uniform distributionHow to get the number of successes given $n$ trials , probability $P$ and a random variable $X$Absorbing Markov chain in a computer. Is “almost every” turned into always convergence in computer executions?Stopped random walk is not uniformly integrable

            Lowndes Grove History Architecture References Navigation menu32°48′6″N 79°57′58″W / 32.80167°N 79.96611°W / 32.80167; -79.9661132°48′6″N 79°57′58″W / 32.80167°N 79.96611°W / 32.80167; -79.9661178002500"National Register Information System"Historic houses of South Carolina"Lowndes Grove""+32° 48' 6.00", −79° 57' 58.00""Lowndes Grove, Charleston County (260 St. Margaret St., Charleston)""Lowndes Grove"The Charleston ExpositionIt Happened in South Carolina"Lowndes Grove (House), Saint Margaret Street & Sixth Avenue, Charleston, Charleston County, SC(Photographs)"Plantations of the Carolina Low Countrye