A question about vector space, sub-spaces and linear transformation
$begingroup$
I have a homework question that I don't know how to start:
let $V$ be a vector space under field $F$, $dim(V) = n$.
let $T: V to V$ be a linear transformation.
prove if $U subseteq V$, and $dim(U) = k$, such that for every $u in U$, $T(u) in U$, then there exists a basis $B$ of $V$ such that:
$[T]^B_B =$
$
begin{bmatrix}
A_1 & A_3 \
0 & A_2 \
end{bmatrix}
$
So that $A_3 ∈ M_{k×(n−k)}(F)$, $A_2 in M_{(n−k)×(n−k)}(F)$ and $A_1 in M_{k×k}(F)$
Thank you for your help!
linear-algebra matrices vector-spaces linear-transformations
$endgroup$
add a comment |
$begingroup$
I have a homework question that I don't know how to start:
let $V$ be a vector space under field $F$, $dim(V) = n$.
let $T: V to V$ be a linear transformation.
prove if $U subseteq V$, and $dim(U) = k$, such that for every $u in U$, $T(u) in U$, then there exists a basis $B$ of $V$ such that:
$[T]^B_B =$
$
begin{bmatrix}
A_1 & A_3 \
0 & A_2 \
end{bmatrix}
$
So that $A_3 ∈ M_{k×(n−k)}(F)$, $A_2 in M_{(n−k)×(n−k)}(F)$ and $A_1 in M_{k×k}(F)$
Thank you for your help!
linear-algebra matrices vector-spaces linear-transformations
$endgroup$
1
$begingroup$
Please use MathJax to format your post so it's easier to read.
$endgroup$
– saulspatz
Jan 2 at 20:17
1
$begingroup$
I edited it, it just took me some time.
$endgroup$
– assaf
Jan 2 at 20:27
add a comment |
$begingroup$
I have a homework question that I don't know how to start:
let $V$ be a vector space under field $F$, $dim(V) = n$.
let $T: V to V$ be a linear transformation.
prove if $U subseteq V$, and $dim(U) = k$, such that for every $u in U$, $T(u) in U$, then there exists a basis $B$ of $V$ such that:
$[T]^B_B =$
$
begin{bmatrix}
A_1 & A_3 \
0 & A_2 \
end{bmatrix}
$
So that $A_3 ∈ M_{k×(n−k)}(F)$, $A_2 in M_{(n−k)×(n−k)}(F)$ and $A_1 in M_{k×k}(F)$
Thank you for your help!
linear-algebra matrices vector-spaces linear-transformations
$endgroup$
I have a homework question that I don't know how to start:
let $V$ be a vector space under field $F$, $dim(V) = n$.
let $T: V to V$ be a linear transformation.
prove if $U subseteq V$, and $dim(U) = k$, such that for every $u in U$, $T(u) in U$, then there exists a basis $B$ of $V$ such that:
$[T]^B_B =$
$
begin{bmatrix}
A_1 & A_3 \
0 & A_2 \
end{bmatrix}
$
So that $A_3 ∈ M_{k×(n−k)}(F)$, $A_2 in M_{(n−k)×(n−k)}(F)$ and $A_1 in M_{k×k}(F)$
Thank you for your help!
linear-algebra matrices vector-spaces linear-transformations
linear-algebra matrices vector-spaces linear-transformations
edited Jan 2 at 21:33


A.Γ.
22.7k32656
22.7k32656
asked Jan 2 at 20:09
assafassaf
133
133
1
$begingroup$
Please use MathJax to format your post so it's easier to read.
$endgroup$
– saulspatz
Jan 2 at 20:17
1
$begingroup$
I edited it, it just took me some time.
$endgroup$
– assaf
Jan 2 at 20:27
add a comment |
1
$begingroup$
Please use MathJax to format your post so it's easier to read.
$endgroup$
– saulspatz
Jan 2 at 20:17
1
$begingroup$
I edited it, it just took me some time.
$endgroup$
– assaf
Jan 2 at 20:27
1
1
$begingroup$
Please use MathJax to format your post so it's easier to read.
$endgroup$
– saulspatz
Jan 2 at 20:17
$begingroup$
Please use MathJax to format your post so it's easier to read.
$endgroup$
– saulspatz
Jan 2 at 20:17
1
1
$begingroup$
I edited it, it just took me some time.
$endgroup$
– assaf
Jan 2 at 20:27
$begingroup$
I edited it, it just took me some time.
$endgroup$
– assaf
Jan 2 at 20:27
add a comment |
3 Answers
3
active
oldest
votes
$begingroup$
Hint: Take a basis $u_1,dots,u_k$ of $U$ and complete it to a basis $u_1,dots,u_k,u_{k+1},dots,u_n$ of $V$.
$endgroup$
add a comment |
$begingroup$
Hint: try to construct the basis $B$. Start with a basis of $U$ ($k$ vectors) and complete it to a basis in $V$ by $n-k$ linearly independent vectors. How does the matrix of $T$ look like in this basis?
$endgroup$
add a comment |
$begingroup$
First you argue that there is a basis of $V$ such that any element of $U$ can be written as $(u_1,dots,u_k,0,dots,0)in V$.
Using this and that by assumption $T(U)subset U$ we deduce that the matrix representation of $T$ in this basis will be:
$$
begin{bmatrix}
A & B \
C & D \
end{bmatrix}
$$
where $A$ is a $ktimes k$ matrix and $C=0$.
$endgroup$
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%2f3059918%2fa-question-about-vector-space-sub-spaces-and-linear-transformation%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Hint: Take a basis $u_1,dots,u_k$ of $U$ and complete it to a basis $u_1,dots,u_k,u_{k+1},dots,u_n$ of $V$.
$endgroup$
add a comment |
$begingroup$
Hint: Take a basis $u_1,dots,u_k$ of $U$ and complete it to a basis $u_1,dots,u_k,u_{k+1},dots,u_n$ of $V$.
$endgroup$
add a comment |
$begingroup$
Hint: Take a basis $u_1,dots,u_k$ of $U$ and complete it to a basis $u_1,dots,u_k,u_{k+1},dots,u_n$ of $V$.
$endgroup$
Hint: Take a basis $u_1,dots,u_k$ of $U$ and complete it to a basis $u_1,dots,u_k,u_{k+1},dots,u_n$ of $V$.
answered Jan 2 at 21:31


ScientificaScientifica
6,37641335
6,37641335
add a comment |
add a comment |
$begingroup$
Hint: try to construct the basis $B$. Start with a basis of $U$ ($k$ vectors) and complete it to a basis in $V$ by $n-k$ linearly independent vectors. How does the matrix of $T$ look like in this basis?
$endgroup$
add a comment |
$begingroup$
Hint: try to construct the basis $B$. Start with a basis of $U$ ($k$ vectors) and complete it to a basis in $V$ by $n-k$ linearly independent vectors. How does the matrix of $T$ look like in this basis?
$endgroup$
add a comment |
$begingroup$
Hint: try to construct the basis $B$. Start with a basis of $U$ ($k$ vectors) and complete it to a basis in $V$ by $n-k$ linearly independent vectors. How does the matrix of $T$ look like in this basis?
$endgroup$
Hint: try to construct the basis $B$. Start with a basis of $U$ ($k$ vectors) and complete it to a basis in $V$ by $n-k$ linearly independent vectors. How does the matrix of $T$ look like in this basis?
answered Jan 2 at 21:31


A.Γ.A.Γ.
22.7k32656
22.7k32656
add a comment |
add a comment |
$begingroup$
First you argue that there is a basis of $V$ such that any element of $U$ can be written as $(u_1,dots,u_k,0,dots,0)in V$.
Using this and that by assumption $T(U)subset U$ we deduce that the matrix representation of $T$ in this basis will be:
$$
begin{bmatrix}
A & B \
C & D \
end{bmatrix}
$$
where $A$ is a $ktimes k$ matrix and $C=0$.
$endgroup$
add a comment |
$begingroup$
First you argue that there is a basis of $V$ such that any element of $U$ can be written as $(u_1,dots,u_k,0,dots,0)in V$.
Using this and that by assumption $T(U)subset U$ we deduce that the matrix representation of $T$ in this basis will be:
$$
begin{bmatrix}
A & B \
C & D \
end{bmatrix}
$$
where $A$ is a $ktimes k$ matrix and $C=0$.
$endgroup$
add a comment |
$begingroup$
First you argue that there is a basis of $V$ such that any element of $U$ can be written as $(u_1,dots,u_k,0,dots,0)in V$.
Using this and that by assumption $T(U)subset U$ we deduce that the matrix representation of $T$ in this basis will be:
$$
begin{bmatrix}
A & B \
C & D \
end{bmatrix}
$$
where $A$ is a $ktimes k$ matrix and $C=0$.
$endgroup$
First you argue that there is a basis of $V$ such that any element of $U$ can be written as $(u_1,dots,u_k,0,dots,0)in V$.
Using this and that by assumption $T(U)subset U$ we deduce that the matrix representation of $T$ in this basis will be:
$$
begin{bmatrix}
A & B \
C & D \
end{bmatrix}
$$
where $A$ is a $ktimes k$ matrix and $C=0$.
answered Jan 2 at 21:46
Test123Test123
2,762828
2,762828
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%2f3059918%2fa-question-about-vector-space-sub-spaces-and-linear-transformation%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
1
$begingroup$
Please use MathJax to format your post so it's easier to read.
$endgroup$
– saulspatz
Jan 2 at 20:17
1
$begingroup$
I edited it, it just took me some time.
$endgroup$
– assaf
Jan 2 at 20:27