Determining $x_2$ in the solution of the system
$begingroup$
Task:
Determine $x_2$ in the solution of the system$$
begin{bmatrix}4&a&0\6&b&2\9&c&3end{bmatrix}begin{bmatrix}x_1\x_2\x_3end{bmatrix}=begin{bmatrix}1\2\0end{bmatrix}$$when$$
left|begin{matrix}4&a&0\6&b&2\9&c&3end{matrix}right|=4$$
using Cramer's rule.
Options to choose from:
- $-4$
- $4$
- $6$
- $-2$
My answer:
$$begin{bmatrix}x_1\x_2\x_3end{bmatrix}×4=begin{bmatrix}1\2\0end{bmatrix}$$
I got $x_2=dfrac24$ which is not an option to choose. How do I do?
linear-algebra systems-of-equations
$endgroup$
add a comment |
$begingroup$
Task:
Determine $x_2$ in the solution of the system$$
begin{bmatrix}4&a&0\6&b&2\9&c&3end{bmatrix}begin{bmatrix}x_1\x_2\x_3end{bmatrix}=begin{bmatrix}1\2\0end{bmatrix}$$when$$
left|begin{matrix}4&a&0\6&b&2\9&c&3end{matrix}right|=4$$
using Cramer's rule.
Options to choose from:
- $-4$
- $4$
- $6$
- $-2$
My answer:
$$begin{bmatrix}x_1\x_2\x_3end{bmatrix}×4=begin{bmatrix}1\2\0end{bmatrix}$$
I got $x_2=dfrac24$ which is not an option to choose. How do I do?
linear-algebra systems-of-equations
$endgroup$
$begingroup$
Do you mean determinant of matrix is $4$?
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:35
$begingroup$
The information that I get from the task is that the 3x3 matrix is equal to 4
$endgroup$
– anders
Dec 20 '18 at 9:37
$begingroup$
The vertical lines are just another notion for the determinant of a matrix.
$endgroup$
– Student7
Dec 20 '18 at 10:22
add a comment |
$begingroup$
Task:
Determine $x_2$ in the solution of the system$$
begin{bmatrix}4&a&0\6&b&2\9&c&3end{bmatrix}begin{bmatrix}x_1\x_2\x_3end{bmatrix}=begin{bmatrix}1\2\0end{bmatrix}$$when$$
left|begin{matrix}4&a&0\6&b&2\9&c&3end{matrix}right|=4$$
using Cramer's rule.
Options to choose from:
- $-4$
- $4$
- $6$
- $-2$
My answer:
$$begin{bmatrix}x_1\x_2\x_3end{bmatrix}×4=begin{bmatrix}1\2\0end{bmatrix}$$
I got $x_2=dfrac24$ which is not an option to choose. How do I do?
linear-algebra systems-of-equations
$endgroup$
Task:
Determine $x_2$ in the solution of the system$$
begin{bmatrix}4&a&0\6&b&2\9&c&3end{bmatrix}begin{bmatrix}x_1\x_2\x_3end{bmatrix}=begin{bmatrix}1\2\0end{bmatrix}$$when$$
left|begin{matrix}4&a&0\6&b&2\9&c&3end{matrix}right|=4$$
using Cramer's rule.
Options to choose from:
- $-4$
- $4$
- $6$
- $-2$
My answer:
$$begin{bmatrix}x_1\x_2\x_3end{bmatrix}×4=begin{bmatrix}1\2\0end{bmatrix}$$
I got $x_2=dfrac24$ which is not an option to choose. How do I do?
linear-algebra systems-of-equations
linear-algebra systems-of-equations
edited Dec 20 '18 at 10:01
Yadati Kiran
1,7911619
1,7911619
asked Dec 20 '18 at 9:30
andersanders
615
615
$begingroup$
Do you mean determinant of matrix is $4$?
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:35
$begingroup$
The information that I get from the task is that the 3x3 matrix is equal to 4
$endgroup$
– anders
Dec 20 '18 at 9:37
$begingroup$
The vertical lines are just another notion for the determinant of a matrix.
$endgroup$
– Student7
Dec 20 '18 at 10:22
add a comment |
$begingroup$
Do you mean determinant of matrix is $4$?
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:35
$begingroup$
The information that I get from the task is that the 3x3 matrix is equal to 4
$endgroup$
– anders
Dec 20 '18 at 9:37
$begingroup$
The vertical lines are just another notion for the determinant of a matrix.
$endgroup$
– Student7
Dec 20 '18 at 10:22
$begingroup$
Do you mean determinant of matrix is $4$?
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:35
$begingroup$
Do you mean determinant of matrix is $4$?
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:35
$begingroup$
The information that I get from the task is that the 3x3 matrix is equal to 4
$endgroup$
– anders
Dec 20 '18 at 9:37
$begingroup$
The information that I get from the task is that the 3x3 matrix is equal to 4
$endgroup$
– anders
Dec 20 '18 at 9:37
$begingroup$
The vertical lines are just another notion for the determinant of a matrix.
$endgroup$
– Student7
Dec 20 '18 at 10:22
$begingroup$
The vertical lines are just another notion for the determinant of a matrix.
$endgroup$
– Student7
Dec 20 '18 at 10:22
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.
$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$
$endgroup$
$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41
$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41
$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43
$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44
$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45
|
show 2 more comments
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%2f3047341%2fdetermining-x-2-in-the-solution-of-the-system%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
$begingroup$
$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.
$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$
$endgroup$
$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41
$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41
$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43
$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44
$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45
|
show 2 more comments
$begingroup$
$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.
$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$
$endgroup$
$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41
$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41
$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43
$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44
$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45
|
show 2 more comments
$begingroup$
$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.
$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$
$endgroup$
$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.
$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$
edited Dec 20 '18 at 10:08
answered Dec 20 '18 at 9:38
Yadati KiranYadati Kiran
1,7911619
1,7911619
$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41
$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41
$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43
$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44
$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45
|
show 2 more comments
$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41
$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41
$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43
$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44
$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45
$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41
$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41
$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41
$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41
$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43
$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43
$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44
$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44
$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45
$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45
|
show 2 more comments
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%2f3047341%2fdetermining-x-2-in-the-solution-of-the-system%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
$begingroup$
Do you mean determinant of matrix is $4$?
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:35
$begingroup$
The information that I get from the task is that the 3x3 matrix is equal to 4
$endgroup$
– anders
Dec 20 '18 at 9:37
$begingroup$
The vertical lines are just another notion for the determinant of a matrix.
$endgroup$
– Student7
Dec 20 '18 at 10:22