Sum of squared differences question The 2019 Stack Overflow Developer Survey Results Are In Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Construct a Confidence Interval of $95%$Why is variance squared?From sample mean and variance of $X$ to $sqrtX$Stuck on the cancellation of sums when calculating sample variance estimatesNumerator of Sample Variance ExpectationDivergence of Chi-squared statisticFor what value of $w$ is $(1-w)bar X_1 + wbar X_2$ the minimum variance unbiased estimator of $mu$R squared formula in linear regressionVariance of the SSBCalculating the MSE of a particular estimator

Word for: a synonym with a positive connotation?

Did God make two great lights or did He make the great light two?

I'm thinking of a number

Simulating Exploding Dice

Does Parliament hold absolute power in the UK?

Mortgage adviser recommends a longer term than necessary combined with overpayments

How is simplicity better than precision and clarity in prose?

Match Roman Numerals

Derivation tree not rendering

What is special about square numbers here?

How to politely respond to generic emails requesting a PhD/job in my lab? Without wasting too much time

What is this lever in Argentinian toilets?

How to pronounce 1ターン?

How long does the line of fire that you can create as an action using the Investiture of Flame spell last?

Does Parliament need to approve the new Brexit delay to 31 October 2019?

rotate text in posterbox

does high air pressure throw off wheel balance?

Make it rain characters

Is it ok to offer lower paid work as a trial period before negotiating for a full-time job?

Did the UK government pay "millions and millions of dollars" to try to snag Julian Assange?

Can the prologue be the backstory of your main character?

Semisimplicity of the category of coherent sheaves?

Is it ethical to upload a automatically generated paper to a non peer-reviewed site as part of a larger research?

Python - Fishing Simulator



Sum of squared differences question



The 2019 Stack Overflow Developer Survey Results Are In
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Construct a Confidence Interval of $95%$Why is variance squared?From sample mean and variance of $X$ to $sqrtX$Stuck on the cancellation of sums when calculating sample variance estimatesNumerator of Sample Variance ExpectationDivergence of Chi-squared statisticFor what value of $w$ is $(1-w)bar X_1 + wbar X_2$ the minimum variance unbiased estimator of $mu$R squared formula in linear regressionVariance of the SSBCalculating the MSE of a particular estimator










0












$begingroup$


I'm completing a homework question and I need to prove the following:



$$
sum_i=1^N ||vecy - vecx_i||^2 = sum_i=1^N ||vecx_i - vecbarx||^2 + N||vecy-vecbarx||^2
$$



where $vecbarx = frac1N sum_i=1^N vecx_i$ and $||cdot||$ is the Euclidean norm and these are all vectors.



I think I probably need to do something similar to the proof for the sample variance but not sure how to modify it when I have a $y$ in now.










share|cite|improve this question











$endgroup$











  • $begingroup$
    Is this an Euclidean norm or a general norm?
    $endgroup$
    – Kavi Rama Murthy
    Mar 25 at 10:10










  • $begingroup$
    This is the Euclidean norm - I should've said, edited the question now
    $endgroup$
    – user-2147482565
    Mar 25 at 10:16






  • 1




    $begingroup$
    If you prove this for $y=0$ you can prove it for any $y$ by changing $x_i$ to $x_i-y$. For $y=0$ use brute force.
    $endgroup$
    – Kavi Rama Murthy
    Mar 25 at 10:24
















0












$begingroup$


I'm completing a homework question and I need to prove the following:



$$
sum_i=1^N ||vecy - vecx_i||^2 = sum_i=1^N ||vecx_i - vecbarx||^2 + N||vecy-vecbarx||^2
$$



where $vecbarx = frac1N sum_i=1^N vecx_i$ and $||cdot||$ is the Euclidean norm and these are all vectors.



I think I probably need to do something similar to the proof for the sample variance but not sure how to modify it when I have a $y$ in now.










share|cite|improve this question











$endgroup$











  • $begingroup$
    Is this an Euclidean norm or a general norm?
    $endgroup$
    – Kavi Rama Murthy
    Mar 25 at 10:10










  • $begingroup$
    This is the Euclidean norm - I should've said, edited the question now
    $endgroup$
    – user-2147482565
    Mar 25 at 10:16






  • 1




    $begingroup$
    If you prove this for $y=0$ you can prove it for any $y$ by changing $x_i$ to $x_i-y$. For $y=0$ use brute force.
    $endgroup$
    – Kavi Rama Murthy
    Mar 25 at 10:24














0












0








0





$begingroup$


I'm completing a homework question and I need to prove the following:



$$
sum_i=1^N ||vecy - vecx_i||^2 = sum_i=1^N ||vecx_i - vecbarx||^2 + N||vecy-vecbarx||^2
$$



where $vecbarx = frac1N sum_i=1^N vecx_i$ and $||cdot||$ is the Euclidean norm and these are all vectors.



I think I probably need to do something similar to the proof for the sample variance but not sure how to modify it when I have a $y$ in now.










share|cite|improve this question











$endgroup$




I'm completing a homework question and I need to prove the following:



$$
sum_i=1^N ||vecy - vecx_i||^2 = sum_i=1^N ||vecx_i - vecbarx||^2 + N||vecy-vecbarx||^2
$$



where $vecbarx = frac1N sum_i=1^N vecx_i$ and $||cdot||$ is the Euclidean norm and these are all vectors.



I think I probably need to do something similar to the proof for the sample variance but not sure how to modify it when I have a $y$ in now.







statistics summation proof-explanation statistical-inference






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Mar 25 at 16:32







user-2147482565

















asked Mar 25 at 10:06









user-2147482565user-2147482565

133




133











  • $begingroup$
    Is this an Euclidean norm or a general norm?
    $endgroup$
    – Kavi Rama Murthy
    Mar 25 at 10:10










  • $begingroup$
    This is the Euclidean norm - I should've said, edited the question now
    $endgroup$
    – user-2147482565
    Mar 25 at 10:16






  • 1




    $begingroup$
    If you prove this for $y=0$ you can prove it for any $y$ by changing $x_i$ to $x_i-y$. For $y=0$ use brute force.
    $endgroup$
    – Kavi Rama Murthy
    Mar 25 at 10:24

















  • $begingroup$
    Is this an Euclidean norm or a general norm?
    $endgroup$
    – Kavi Rama Murthy
    Mar 25 at 10:10










  • $begingroup$
    This is the Euclidean norm - I should've said, edited the question now
    $endgroup$
    – user-2147482565
    Mar 25 at 10:16






  • 1




    $begingroup$
    If you prove this for $y=0$ you can prove it for any $y$ by changing $x_i$ to $x_i-y$. For $y=0$ use brute force.
    $endgroup$
    – Kavi Rama Murthy
    Mar 25 at 10:24
















$begingroup$
Is this an Euclidean norm or a general norm?
$endgroup$
– Kavi Rama Murthy
Mar 25 at 10:10




$begingroup$
Is this an Euclidean norm or a general norm?
$endgroup$
– Kavi Rama Murthy
Mar 25 at 10:10












$begingroup$
This is the Euclidean norm - I should've said, edited the question now
$endgroup$
– user-2147482565
Mar 25 at 10:16




$begingroup$
This is the Euclidean norm - I should've said, edited the question now
$endgroup$
– user-2147482565
Mar 25 at 10:16




1




1




$begingroup$
If you prove this for $y=0$ you can prove it for any $y$ by changing $x_i$ to $x_i-y$. For $y=0$ use brute force.
$endgroup$
– Kavi Rama Murthy
Mar 25 at 10:24





$begingroup$
If you prove this for $y=0$ you can prove it for any $y$ by changing $x_i$ to $x_i-y$. For $y=0$ use brute force.
$endgroup$
– Kavi Rama Murthy
Mar 25 at 10:24











2 Answers
2






active

oldest

votes


















1












$begingroup$

Hint:



$$(y-x_i)(y-x_i)=((y-overline x)+(overline x-x_i))((y-overline x)+(overline x-x_i))
\=(y-overline x)(y-overline x)+2(y-overline x)(overline x-x_i)+(overline x-x_i)(overline x-x_i).$$



Now take the average over $i$.






share|cite|improve this answer









$endgroup$












  • $begingroup$
    But I have norms here, if I take the sum over $i$ and we have norms instead of brackets, how does the cross products cancel out?
    $endgroup$
    – user-2147482565
    Mar 25 at 12:38










  • $begingroup$
    @RyanChan: there are no cross products here.
    $endgroup$
    – Yves Daoust
    Mar 25 at 13:07











  • $begingroup$
    Sorry, I meant cross product not as in the dot product, but the terms $2||y-barx|| ||barx-x_i||$
    $endgroup$
    – user-2147482565
    Mar 25 at 13:11











  • $begingroup$
    @RyanChan: there are no such terms in the development. When averaging, the middle dot product cancels out.
    $endgroup$
    – Yves Daoust
    Mar 25 at 13:12











  • $begingroup$
    Sorry I'm just confused - the term is in the hint that you gave?
    $endgroup$
    – user-2147482565
    Mar 25 at 13:13


















0












$begingroup$

beginalign*
sum_i=1^N ||vecy - vecx_i||^2 & = sum_i=1^N ||(vecy - vecbarx_i) + (vecbarx - vecx_i)||^2 \
& = sum_i=1^N ((vecy - vecbarx) + (vecbarx - vecx_i)) ((vecy - vecbarx) + (vecbarx - vecx_i))^T \
& = sum_i=1^N (vecy - vecbarx)(vecy - vecbarx)^T + 2 sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T + sum_i=1^N (vecbarx - vecx_i)(vecbarx - vecx_i)^T \
& = sum_i=1^N || vecbarx - vecx_i ||^2 + N ||vecy - vecbarx||^2
endalign*



since



beginalign*
sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T & = sum_i=1^N sum_j (y_j - barx_j)(barx_j - x_ij) \
& = sum_i=1^N sum_j (y_jbarx_j - y_jx_ij - barx_j^2 + barx_jx_ij) \
& = sum_j Bigg[ Ny_jbarx_j - y_j sum_i=1^Nx_ij - Nbarx_j^2 + barx_jsum_i=1^Nx_ij Bigg] \
& = sum_j Bigg[ Ny_jbarx_j - y_jNbarx_j - N barx_j^2 + barx_jNbarx_j Bigg] \
& = sum_j 0 \
& = 0
endalign*






share|cite|improve this answer











$endgroup$













    Your Answer








    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%2f3161595%2fsum-of-squared-differences-question%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









    1












    $begingroup$

    Hint:



    $$(y-x_i)(y-x_i)=((y-overline x)+(overline x-x_i))((y-overline x)+(overline x-x_i))
    \=(y-overline x)(y-overline x)+2(y-overline x)(overline x-x_i)+(overline x-x_i)(overline x-x_i).$$



    Now take the average over $i$.






    share|cite|improve this answer









    $endgroup$












    • $begingroup$
      But I have norms here, if I take the sum over $i$ and we have norms instead of brackets, how does the cross products cancel out?
      $endgroup$
      – user-2147482565
      Mar 25 at 12:38










    • $begingroup$
      @RyanChan: there are no cross products here.
      $endgroup$
      – Yves Daoust
      Mar 25 at 13:07











    • $begingroup$
      Sorry, I meant cross product not as in the dot product, but the terms $2||y-barx|| ||barx-x_i||$
      $endgroup$
      – user-2147482565
      Mar 25 at 13:11











    • $begingroup$
      @RyanChan: there are no such terms in the development. When averaging, the middle dot product cancels out.
      $endgroup$
      – Yves Daoust
      Mar 25 at 13:12











    • $begingroup$
      Sorry I'm just confused - the term is in the hint that you gave?
      $endgroup$
      – user-2147482565
      Mar 25 at 13:13















    1












    $begingroup$

    Hint:



    $$(y-x_i)(y-x_i)=((y-overline x)+(overline x-x_i))((y-overline x)+(overline x-x_i))
    \=(y-overline x)(y-overline x)+2(y-overline x)(overline x-x_i)+(overline x-x_i)(overline x-x_i).$$



    Now take the average over $i$.






    share|cite|improve this answer









    $endgroup$












    • $begingroup$
      But I have norms here, if I take the sum over $i$ and we have norms instead of brackets, how does the cross products cancel out?
      $endgroup$
      – user-2147482565
      Mar 25 at 12:38










    • $begingroup$
      @RyanChan: there are no cross products here.
      $endgroup$
      – Yves Daoust
      Mar 25 at 13:07











    • $begingroup$
      Sorry, I meant cross product not as in the dot product, but the terms $2||y-barx|| ||barx-x_i||$
      $endgroup$
      – user-2147482565
      Mar 25 at 13:11











    • $begingroup$
      @RyanChan: there are no such terms in the development. When averaging, the middle dot product cancels out.
      $endgroup$
      – Yves Daoust
      Mar 25 at 13:12











    • $begingroup$
      Sorry I'm just confused - the term is in the hint that you gave?
      $endgroup$
      – user-2147482565
      Mar 25 at 13:13













    1












    1








    1





    $begingroup$

    Hint:



    $$(y-x_i)(y-x_i)=((y-overline x)+(overline x-x_i))((y-overline x)+(overline x-x_i))
    \=(y-overline x)(y-overline x)+2(y-overline x)(overline x-x_i)+(overline x-x_i)(overline x-x_i).$$



    Now take the average over $i$.






    share|cite|improve this answer









    $endgroup$



    Hint:



    $$(y-x_i)(y-x_i)=((y-overline x)+(overline x-x_i))((y-overline x)+(overline x-x_i))
    \=(y-overline x)(y-overline x)+2(y-overline x)(overline x-x_i)+(overline x-x_i)(overline x-x_i).$$



    Now take the average over $i$.







    share|cite|improve this answer












    share|cite|improve this answer



    share|cite|improve this answer










    answered Mar 25 at 11:06









    Yves DaoustYves Daoust

    133k676231




    133k676231











    • $begingroup$
      But I have norms here, if I take the sum over $i$ and we have norms instead of brackets, how does the cross products cancel out?
      $endgroup$
      – user-2147482565
      Mar 25 at 12:38










    • $begingroup$
      @RyanChan: there are no cross products here.
      $endgroup$
      – Yves Daoust
      Mar 25 at 13:07











    • $begingroup$
      Sorry, I meant cross product not as in the dot product, but the terms $2||y-barx|| ||barx-x_i||$
      $endgroup$
      – user-2147482565
      Mar 25 at 13:11











    • $begingroup$
      @RyanChan: there are no such terms in the development. When averaging, the middle dot product cancels out.
      $endgroup$
      – Yves Daoust
      Mar 25 at 13:12











    • $begingroup$
      Sorry I'm just confused - the term is in the hint that you gave?
      $endgroup$
      – user-2147482565
      Mar 25 at 13:13
















    • $begingroup$
      But I have norms here, if I take the sum over $i$ and we have norms instead of brackets, how does the cross products cancel out?
      $endgroup$
      – user-2147482565
      Mar 25 at 12:38










    • $begingroup$
      @RyanChan: there are no cross products here.
      $endgroup$
      – Yves Daoust
      Mar 25 at 13:07











    • $begingroup$
      Sorry, I meant cross product not as in the dot product, but the terms $2||y-barx|| ||barx-x_i||$
      $endgroup$
      – user-2147482565
      Mar 25 at 13:11











    • $begingroup$
      @RyanChan: there are no such terms in the development. When averaging, the middle dot product cancels out.
      $endgroup$
      – Yves Daoust
      Mar 25 at 13:12











    • $begingroup$
      Sorry I'm just confused - the term is in the hint that you gave?
      $endgroup$
      – user-2147482565
      Mar 25 at 13:13















    $begingroup$
    But I have norms here, if I take the sum over $i$ and we have norms instead of brackets, how does the cross products cancel out?
    $endgroup$
    – user-2147482565
    Mar 25 at 12:38




    $begingroup$
    But I have norms here, if I take the sum over $i$ and we have norms instead of brackets, how does the cross products cancel out?
    $endgroup$
    – user-2147482565
    Mar 25 at 12:38












    $begingroup$
    @RyanChan: there are no cross products here.
    $endgroup$
    – Yves Daoust
    Mar 25 at 13:07





    $begingroup$
    @RyanChan: there are no cross products here.
    $endgroup$
    – Yves Daoust
    Mar 25 at 13:07













    $begingroup$
    Sorry, I meant cross product not as in the dot product, but the terms $2||y-barx|| ||barx-x_i||$
    $endgroup$
    – user-2147482565
    Mar 25 at 13:11





    $begingroup$
    Sorry, I meant cross product not as in the dot product, but the terms $2||y-barx|| ||barx-x_i||$
    $endgroup$
    – user-2147482565
    Mar 25 at 13:11













    $begingroup$
    @RyanChan: there are no such terms in the development. When averaging, the middle dot product cancels out.
    $endgroup$
    – Yves Daoust
    Mar 25 at 13:12





    $begingroup$
    @RyanChan: there are no such terms in the development. When averaging, the middle dot product cancels out.
    $endgroup$
    – Yves Daoust
    Mar 25 at 13:12













    $begingroup$
    Sorry I'm just confused - the term is in the hint that you gave?
    $endgroup$
    – user-2147482565
    Mar 25 at 13:13




    $begingroup$
    Sorry I'm just confused - the term is in the hint that you gave?
    $endgroup$
    – user-2147482565
    Mar 25 at 13:13











    0












    $begingroup$

    beginalign*
    sum_i=1^N ||vecy - vecx_i||^2 & = sum_i=1^N ||(vecy - vecbarx_i) + (vecbarx - vecx_i)||^2 \
    & = sum_i=1^N ((vecy - vecbarx) + (vecbarx - vecx_i)) ((vecy - vecbarx) + (vecbarx - vecx_i))^T \
    & = sum_i=1^N (vecy - vecbarx)(vecy - vecbarx)^T + 2 sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T + sum_i=1^N (vecbarx - vecx_i)(vecbarx - vecx_i)^T \
    & = sum_i=1^N || vecbarx - vecx_i ||^2 + N ||vecy - vecbarx||^2
    endalign*



    since



    beginalign*
    sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T & = sum_i=1^N sum_j (y_j - barx_j)(barx_j - x_ij) \
    & = sum_i=1^N sum_j (y_jbarx_j - y_jx_ij - barx_j^2 + barx_jx_ij) \
    & = sum_j Bigg[ Ny_jbarx_j - y_j sum_i=1^Nx_ij - Nbarx_j^2 + barx_jsum_i=1^Nx_ij Bigg] \
    & = sum_j Bigg[ Ny_jbarx_j - y_jNbarx_j - N barx_j^2 + barx_jNbarx_j Bigg] \
    & = sum_j 0 \
    & = 0
    endalign*






    share|cite|improve this answer











    $endgroup$

















      0












      $begingroup$

      beginalign*
      sum_i=1^N ||vecy - vecx_i||^2 & = sum_i=1^N ||(vecy - vecbarx_i) + (vecbarx - vecx_i)||^2 \
      & = sum_i=1^N ((vecy - vecbarx) + (vecbarx - vecx_i)) ((vecy - vecbarx) + (vecbarx - vecx_i))^T \
      & = sum_i=1^N (vecy - vecbarx)(vecy - vecbarx)^T + 2 sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T + sum_i=1^N (vecbarx - vecx_i)(vecbarx - vecx_i)^T \
      & = sum_i=1^N || vecbarx - vecx_i ||^2 + N ||vecy - vecbarx||^2
      endalign*



      since



      beginalign*
      sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T & = sum_i=1^N sum_j (y_j - barx_j)(barx_j - x_ij) \
      & = sum_i=1^N sum_j (y_jbarx_j - y_jx_ij - barx_j^2 + barx_jx_ij) \
      & = sum_j Bigg[ Ny_jbarx_j - y_j sum_i=1^Nx_ij - Nbarx_j^2 + barx_jsum_i=1^Nx_ij Bigg] \
      & = sum_j Bigg[ Ny_jbarx_j - y_jNbarx_j - N barx_j^2 + barx_jNbarx_j Bigg] \
      & = sum_j 0 \
      & = 0
      endalign*






      share|cite|improve this answer











      $endgroup$















        0












        0








        0





        $begingroup$

        beginalign*
        sum_i=1^N ||vecy - vecx_i||^2 & = sum_i=1^N ||(vecy - vecbarx_i) + (vecbarx - vecx_i)||^2 \
        & = sum_i=1^N ((vecy - vecbarx) + (vecbarx - vecx_i)) ((vecy - vecbarx) + (vecbarx - vecx_i))^T \
        & = sum_i=1^N (vecy - vecbarx)(vecy - vecbarx)^T + 2 sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T + sum_i=1^N (vecbarx - vecx_i)(vecbarx - vecx_i)^T \
        & = sum_i=1^N || vecbarx - vecx_i ||^2 + N ||vecy - vecbarx||^2
        endalign*



        since



        beginalign*
        sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T & = sum_i=1^N sum_j (y_j - barx_j)(barx_j - x_ij) \
        & = sum_i=1^N sum_j (y_jbarx_j - y_jx_ij - barx_j^2 + barx_jx_ij) \
        & = sum_j Bigg[ Ny_jbarx_j - y_j sum_i=1^Nx_ij - Nbarx_j^2 + barx_jsum_i=1^Nx_ij Bigg] \
        & = sum_j Bigg[ Ny_jbarx_j - y_jNbarx_j - N barx_j^2 + barx_jNbarx_j Bigg] \
        & = sum_j 0 \
        & = 0
        endalign*






        share|cite|improve this answer











        $endgroup$



        beginalign*
        sum_i=1^N ||vecy - vecx_i||^2 & = sum_i=1^N ||(vecy - vecbarx_i) + (vecbarx - vecx_i)||^2 \
        & = sum_i=1^N ((vecy - vecbarx) + (vecbarx - vecx_i)) ((vecy - vecbarx) + (vecbarx - vecx_i))^T \
        & = sum_i=1^N (vecy - vecbarx)(vecy - vecbarx)^T + 2 sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T + sum_i=1^N (vecbarx - vecx_i)(vecbarx - vecx_i)^T \
        & = sum_i=1^N || vecbarx - vecx_i ||^2 + N ||vecy - vecbarx||^2
        endalign*



        since



        beginalign*
        sum_i=1^N (vecy - vecbarx)(vecbarx - vecx_i)^T & = sum_i=1^N sum_j (y_j - barx_j)(barx_j - x_ij) \
        & = sum_i=1^N sum_j (y_jbarx_j - y_jx_ij - barx_j^2 + barx_jx_ij) \
        & = sum_j Bigg[ Ny_jbarx_j - y_j sum_i=1^Nx_ij - Nbarx_j^2 + barx_jsum_i=1^Nx_ij Bigg] \
        & = sum_j Bigg[ Ny_jbarx_j - y_jNbarx_j - N barx_j^2 + barx_jNbarx_j Bigg] \
        & = sum_j 0 \
        & = 0
        endalign*







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Mar 26 at 10:15

























        answered Mar 26 at 9:14









        user-2147482565user-2147482565

        133




        133



























            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%2f3161595%2fsum-of-squared-differences-question%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

            Solar Wings Breeze Design and development Specifications (Breeze) References Navigation menu1368-485X"Hang glider: Breeze (Solar Wings)"e

            Kathakali Contents Etymology and nomenclature History Repertoire Songs and musical instruments Traditional plays Styles: Sampradayam Training centers and awards Relationship to other dance forms See also Notes References External links Navigation menueThe Illustrated Encyclopedia of Hinduism: A-MSouth Asian Folklore: An EncyclopediaRoutledge International Encyclopedia of Women: Global Women's Issues and KnowledgeKathakali Dance-drama: Where Gods and Demons Come to PlayKathakali Dance-drama: Where Gods and Demons Come to PlayKathakali Dance-drama: Where Gods and Demons Come to Play10.1353/atj.2005.0004The Illustrated Encyclopedia of Hinduism: A-MEncyclopedia of HinduismKathakali Dance-drama: Where Gods and Demons Come to PlaySonic Liturgy: Ritual and Music in Hindu Tradition"The Mirror of Gesture"Kathakali Dance-drama: Where Gods and Demons Come to Play"Kathakali"Indian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceMedieval Indian Literature: An AnthologyThe Oxford Companion to Indian TheatreSouth Asian Folklore: An Encyclopedia : Afghanistan, Bangladesh, India, Nepal, Pakistan, Sri LankaThe Rise of Performance Studies: Rethinking Richard Schechner's Broad SpectrumIndian Theatre: Traditions of PerformanceModern Asian Theatre and Performance 1900-2000Critical Theory and PerformanceBetween Theater and AnthropologyKathakali603847011Indian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceIndian Theatre: Traditions of PerformanceBetween Theater and AnthropologyBetween Theater and AnthropologyNambeesan Smaraka AwardsArchivedThe Cambridge Guide to TheatreRoutledge International Encyclopedia of Women: Global Women's Issues and KnowledgeThe Garland Encyclopedia of World Music: South Asia : the Indian subcontinentThe Ethos of Noh: Actors and Their Art10.2307/1145740By Means of Performance: Intercultural Studies of Theatre and Ritual10.1017/s204912550000100xReconceiving the Renaissance: A Critical ReaderPerformance TheoryListening to Theatre: The Aural Dimension of Beijing Opera10.2307/1146013Kathakali: The Art of the Non-WorldlyOn KathakaliKathakali, the dance theatreThe Kathakali Complex: Performance & StructureKathakali Dance-Drama: Where Gods and Demons Come to Play10.1093/obo/9780195399318-0071Drama and Ritual of Early Hinduism"In the Shadow of Hollywood Orientalism: Authentic East Indian Dancing"10.1080/08949460490274013Sanskrit Play Production in Ancient IndiaIndian Music: History and StructureBharata, the Nāṭyaśāstra233639306Table of Contents2238067286469807Dance In Indian Painting10.2307/32047833204783Kathakali Dance-Theatre: A Visual Narrative of Sacred Indian MimeIndian Classical Dance: The Renaissance and BeyondKathakali: an indigenous art-form of Keralaeee

            Method to test if a number is a perfect power? Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern)Detecting perfect squares faster than by extracting square rooteffective way to get the integer sequence A181392 from oeisA rarely mentioned fact about perfect powersHow many numbers such $n$ are there that $n<100,lfloorsqrtn rfloor mid n$Check perfect squareness by modulo division against multiple basesFor what pair of integers $(a,b)$ is $3^a + 7^b$ a perfect square.Do there exist any positive integers $n$ such that $lfloore^nrfloor$ is a perfect power? What is the probability that one exists?finding perfect power factors of an integerProve that the sequence contains a perfect square for any natural number $m $ in the domain of $f$ .Counting Perfect Powers