Values to whom the matrix is diagonalizable and invertible
$begingroup$
I've got this matrix A=$$begin{bmatrix} 2&0&3\0&L&0\4&0&0end{bmatrix}$$
And I must to find the values for what this matrix is diagonalizable and they are 5 and 1 with geometrical and algebrica molteplicity equal 2. And for all of them this matrix is diagonalizable. But I can't understand the second part of this exercise. I must to find the values for what this matrix is invertible and 5|A^-1|>=tr(A)-6. So I find the invertible matrix because the determinant it's different from 0. And this matrix is $$begin{bmatrix} 8&0&4\0&5&0\-3&0&8end{bmatrix}$$ (I used the value L=1 in this case. And |A^-1|=0*0-5*4=-20 so 5|A^-1|=-100 and tr(A)-6=2+1+4=7-6=1 and here I think to do something wrong, and I can't find the correct solution for the second part of this exercise. I try to search on web.
matrix-equations matrix-calculus
$endgroup$
add a comment |
$begingroup$
I've got this matrix A=$$begin{bmatrix} 2&0&3\0&L&0\4&0&0end{bmatrix}$$
And I must to find the values for what this matrix is diagonalizable and they are 5 and 1 with geometrical and algebrica molteplicity equal 2. And for all of them this matrix is diagonalizable. But I can't understand the second part of this exercise. I must to find the values for what this matrix is invertible and 5|A^-1|>=tr(A)-6. So I find the invertible matrix because the determinant it's different from 0. And this matrix is $$begin{bmatrix} 8&0&4\0&5&0\-3&0&8end{bmatrix}$$ (I used the value L=1 in this case. And |A^-1|=0*0-5*4=-20 so 5|A^-1|=-100 and tr(A)-6=2+1+4=7-6=1 and here I think to do something wrong, and I can't find the correct solution for the second part of this exercise. I try to search on web.
matrix-equations matrix-calculus
$endgroup$
add a comment |
$begingroup$
I've got this matrix A=$$begin{bmatrix} 2&0&3\0&L&0\4&0&0end{bmatrix}$$
And I must to find the values for what this matrix is diagonalizable and they are 5 and 1 with geometrical and algebrica molteplicity equal 2. And for all of them this matrix is diagonalizable. But I can't understand the second part of this exercise. I must to find the values for what this matrix is invertible and 5|A^-1|>=tr(A)-6. So I find the invertible matrix because the determinant it's different from 0. And this matrix is $$begin{bmatrix} 8&0&4\0&5&0\-3&0&8end{bmatrix}$$ (I used the value L=1 in this case. And |A^-1|=0*0-5*4=-20 so 5|A^-1|=-100 and tr(A)-6=2+1+4=7-6=1 and here I think to do something wrong, and I can't find the correct solution for the second part of this exercise. I try to search on web.
matrix-equations matrix-calculus
$endgroup$
I've got this matrix A=$$begin{bmatrix} 2&0&3\0&L&0\4&0&0end{bmatrix}$$
And I must to find the values for what this matrix is diagonalizable and they are 5 and 1 with geometrical and algebrica molteplicity equal 2. And for all of them this matrix is diagonalizable. But I can't understand the second part of this exercise. I must to find the values for what this matrix is invertible and 5|A^-1|>=tr(A)-6. So I find the invertible matrix because the determinant it's different from 0. And this matrix is $$begin{bmatrix} 8&0&4\0&5&0\-3&0&8end{bmatrix}$$ (I used the value L=1 in this case. And |A^-1|=0*0-5*4=-20 so 5|A^-1|=-100 and tr(A)-6=2+1+4=7-6=1 and here I think to do something wrong, and I can't find the correct solution for the second part of this exercise. I try to search on web.
matrix-equations matrix-calculus
matrix-equations matrix-calculus
edited Dec 16 '18 at 20:39
Ciao
asked Dec 16 '18 at 20:20
CiaoCiao
94
94
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Your matrix has characteristic polynomial $P(lambda) =lambda^3 - (2+L) lambda^2 - (12 + 2 L) lambda + 12 L$. It is diagonalizable if this has distinct roots. The discriminant of the characteristic polynomial is $52, left( {L}^{2}-2,L-12 right) ^{2}$, so unless $L$ is one of the roots of that ($1 pm sqrt{13}$), the matrix is diagonalizable. But it turns out that for those values of $L$ it is also diagonalizable.
$endgroup$
add a comment |
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
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3043106%2fvalues-to-whom-the-matrix-is-diagonalizable-and-invertible%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
$begingroup$
Your matrix has characteristic polynomial $P(lambda) =lambda^3 - (2+L) lambda^2 - (12 + 2 L) lambda + 12 L$. It is diagonalizable if this has distinct roots. The discriminant of the characteristic polynomial is $52, left( {L}^{2}-2,L-12 right) ^{2}$, so unless $L$ is one of the roots of that ($1 pm sqrt{13}$), the matrix is diagonalizable. But it turns out that for those values of $L$ it is also diagonalizable.
$endgroup$
add a comment |
$begingroup$
Your matrix has characteristic polynomial $P(lambda) =lambda^3 - (2+L) lambda^2 - (12 + 2 L) lambda + 12 L$. It is diagonalizable if this has distinct roots. The discriminant of the characteristic polynomial is $52, left( {L}^{2}-2,L-12 right) ^{2}$, so unless $L$ is one of the roots of that ($1 pm sqrt{13}$), the matrix is diagonalizable. But it turns out that for those values of $L$ it is also diagonalizable.
$endgroup$
add a comment |
$begingroup$
Your matrix has characteristic polynomial $P(lambda) =lambda^3 - (2+L) lambda^2 - (12 + 2 L) lambda + 12 L$. It is diagonalizable if this has distinct roots. The discriminant of the characteristic polynomial is $52, left( {L}^{2}-2,L-12 right) ^{2}$, so unless $L$ is one of the roots of that ($1 pm sqrt{13}$), the matrix is diagonalizable. But it turns out that for those values of $L$ it is also diagonalizable.
$endgroup$
Your matrix has characteristic polynomial $P(lambda) =lambda^3 - (2+L) lambda^2 - (12 + 2 L) lambda + 12 L$. It is diagonalizable if this has distinct roots. The discriminant of the characteristic polynomial is $52, left( {L}^{2}-2,L-12 right) ^{2}$, so unless $L$ is one of the roots of that ($1 pm sqrt{13}$), the matrix is diagonalizable. But it turns out that for those values of $L$ it is also diagonalizable.
edited Dec 16 '18 at 20:45
Rebellos
14.5k31246
14.5k31246
answered Dec 16 '18 at 20:45
Robert IsraelRobert Israel
320k23209461
320k23209461
add a comment |
add a comment |
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.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3043106%2fvalues-to-whom-the-matrix-is-diagonalizable-and-invertible%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
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