If $sum_{i=1}^vu_iotimes v_i =0$ then $v_i=0$ for all $i=1,cdots, n$
up vote
0
down vote
favorite
Let $U$, $V$ be $K$-vector spaces. Let $u_1,cdots, u_nin U$ be linear independent vectors and $v_1,cdots, v_nin V$ arbitrary vectors. Show that if $sum_{i=1}^vu_iotimes v_i =0$ then $v_i=0$ for all $i=1,cdots, n$
I can obviously show the converse, but it does not suffice. I tried to find the answer here but I couldn't. It seems simple but I don't know how to begin
linear-algebra
add a comment |
up vote
0
down vote
favorite
Let $U$, $V$ be $K$-vector spaces. Let $u_1,cdots, u_nin U$ be linear independent vectors and $v_1,cdots, v_nin V$ arbitrary vectors. Show that if $sum_{i=1}^vu_iotimes v_i =0$ then $v_i=0$ for all $i=1,cdots, n$
I can obviously show the converse, but it does not suffice. I tried to find the answer here but I couldn't. It seems simple but I don't know how to begin
linear-algebra
1
Should it be $sum_{i=1}^n$ rather than $sum_{i=1}^v$ in the title and text?
– Semiclassical
Nov 17 at 18:35
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
Let $U$, $V$ be $K$-vector spaces. Let $u_1,cdots, u_nin U$ be linear independent vectors and $v_1,cdots, v_nin V$ arbitrary vectors. Show that if $sum_{i=1}^vu_iotimes v_i =0$ then $v_i=0$ for all $i=1,cdots, n$
I can obviously show the converse, but it does not suffice. I tried to find the answer here but I couldn't. It seems simple but I don't know how to begin
linear-algebra
Let $U$, $V$ be $K$-vector spaces. Let $u_1,cdots, u_nin U$ be linear independent vectors and $v_1,cdots, v_nin V$ arbitrary vectors. Show that if $sum_{i=1}^vu_iotimes v_i =0$ then $v_i=0$ for all $i=1,cdots, n$
I can obviously show the converse, but it does not suffice. I tried to find the answer here but I couldn't. It seems simple but I don't know how to begin
linear-algebra
linear-algebra
asked Nov 17 at 18:07
Guerlando OCs
6821450
6821450
1
Should it be $sum_{i=1}^n$ rather than $sum_{i=1}^v$ in the title and text?
– Semiclassical
Nov 17 at 18:35
add a comment |
1
Should it be $sum_{i=1}^n$ rather than $sum_{i=1}^v$ in the title and text?
– Semiclassical
Nov 17 at 18:35
1
1
Should it be $sum_{i=1}^n$ rather than $sum_{i=1}^v$ in the title and text?
– Semiclassical
Nov 17 at 18:35
Should it be $sum_{i=1}^n$ rather than $sum_{i=1}^v$ in the title and text?
– Semiclassical
Nov 17 at 18:35
add a comment |
1 Answer
1
active
oldest
votes
up vote
1
down vote
accepted
Let $w_1, ldots, w_m$ be a basis of $V$. Then $u_i otimes w_j$ is linearly independent in
$U otimes V$. One can write
$$sum_{i=1}^{n} u_i otimes v_i = sum_{i=1}^{n} u_i otimes left( sum_{j=1}^{m}c^i_j w_jright) = sum_{i=1}^{n} sum_{j=1}^{m} c^i_j (u_i otimes w_j) = 0.$$
Clearly, this implies that all $c^i_j = 0$. Thus, $v_i = sum c^i_j w_j = 0$.
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
1
down vote
accepted
Let $w_1, ldots, w_m$ be a basis of $V$. Then $u_i otimes w_j$ is linearly independent in
$U otimes V$. One can write
$$sum_{i=1}^{n} u_i otimes v_i = sum_{i=1}^{n} u_i otimes left( sum_{j=1}^{m}c^i_j w_jright) = sum_{i=1}^{n} sum_{j=1}^{m} c^i_j (u_i otimes w_j) = 0.$$
Clearly, this implies that all $c^i_j = 0$. Thus, $v_i = sum c^i_j w_j = 0$.
add a comment |
up vote
1
down vote
accepted
Let $w_1, ldots, w_m$ be a basis of $V$. Then $u_i otimes w_j$ is linearly independent in
$U otimes V$. One can write
$$sum_{i=1}^{n} u_i otimes v_i = sum_{i=1}^{n} u_i otimes left( sum_{j=1}^{m}c^i_j w_jright) = sum_{i=1}^{n} sum_{j=1}^{m} c^i_j (u_i otimes w_j) = 0.$$
Clearly, this implies that all $c^i_j = 0$. Thus, $v_i = sum c^i_j w_j = 0$.
add a comment |
up vote
1
down vote
accepted
up vote
1
down vote
accepted
Let $w_1, ldots, w_m$ be a basis of $V$. Then $u_i otimes w_j$ is linearly independent in
$U otimes V$. One can write
$$sum_{i=1}^{n} u_i otimes v_i = sum_{i=1}^{n} u_i otimes left( sum_{j=1}^{m}c^i_j w_jright) = sum_{i=1}^{n} sum_{j=1}^{m} c^i_j (u_i otimes w_j) = 0.$$
Clearly, this implies that all $c^i_j = 0$. Thus, $v_i = sum c^i_j w_j = 0$.
Let $w_1, ldots, w_m$ be a basis of $V$. Then $u_i otimes w_j$ is linearly independent in
$U otimes V$. One can write
$$sum_{i=1}^{n} u_i otimes v_i = sum_{i=1}^{n} u_i otimes left( sum_{j=1}^{m}c^i_j w_jright) = sum_{i=1}^{n} sum_{j=1}^{m} c^i_j (u_i otimes w_j) = 0.$$
Clearly, this implies that all $c^i_j = 0$. Thus, $v_i = sum c^i_j w_j = 0$.
answered Nov 17 at 18:32
Jeffery Opoku-Mensah
3,517719
3,517719
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.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- 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.
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%2f3002635%2fif-sum-i-1vu-i-otimes-v-i-0-then-v-i-0-for-all-i-1-cdots-n%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
Should it be $sum_{i=1}^n$ rather than $sum_{i=1}^v$ in the title and text?
– Semiclassical
Nov 17 at 18:35