Dimension of the null space of an invertible square matrix $A$












1












$begingroup$


Let $A$ be an $m times n$ matrix of real numbers and $cl(A)$ denotes the column space of $A$, $R(A)$ denotes the row space of $A$ and $N(A)$ denotes the Null space of $A$.



I want to prove this statement.
If $m=n$ and $det(A) neq 0$ then $dim(N(A))=0$



My attempt.



An $m times n$ matrix of real numbers is a linear transformation $T: mathbb{R}^n to mathbb{R}^m$



let $m=n=k implies$ $T: mathbb{R}^k to mathbb{R}^k$ Now since the matrix $A$ is invertible $implies$ $T$ has an inverse $T^{-1}$ $implies$ $T$ is injective thus the Null space $N(T)={0} implies $ $dim(N(T))=0$










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    Your proof is correct. Was that your question?
    $endgroup$
    – Jonas
    Dec 22 '18 at 7:08










  • $begingroup$
    I am always suspicious if there is a mistake :)
    $endgroup$
    – Dreamer123
    Dec 22 '18 at 7:12






  • 1




    $begingroup$
    In future, use the proof-verification tag
    $endgroup$
    – Shubham Johri
    Dec 22 '18 at 7:20


















1












$begingroup$


Let $A$ be an $m times n$ matrix of real numbers and $cl(A)$ denotes the column space of $A$, $R(A)$ denotes the row space of $A$ and $N(A)$ denotes the Null space of $A$.



I want to prove this statement.
If $m=n$ and $det(A) neq 0$ then $dim(N(A))=0$



My attempt.



An $m times n$ matrix of real numbers is a linear transformation $T: mathbb{R}^n to mathbb{R}^m$



let $m=n=k implies$ $T: mathbb{R}^k to mathbb{R}^k$ Now since the matrix $A$ is invertible $implies$ $T$ has an inverse $T^{-1}$ $implies$ $T$ is injective thus the Null space $N(T)={0} implies $ $dim(N(T))=0$










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    Your proof is correct. Was that your question?
    $endgroup$
    – Jonas
    Dec 22 '18 at 7:08










  • $begingroup$
    I am always suspicious if there is a mistake :)
    $endgroup$
    – Dreamer123
    Dec 22 '18 at 7:12






  • 1




    $begingroup$
    In future, use the proof-verification tag
    $endgroup$
    – Shubham Johri
    Dec 22 '18 at 7:20
















1












1








1





$begingroup$


Let $A$ be an $m times n$ matrix of real numbers and $cl(A)$ denotes the column space of $A$, $R(A)$ denotes the row space of $A$ and $N(A)$ denotes the Null space of $A$.



I want to prove this statement.
If $m=n$ and $det(A) neq 0$ then $dim(N(A))=0$



My attempt.



An $m times n$ matrix of real numbers is a linear transformation $T: mathbb{R}^n to mathbb{R}^m$



let $m=n=k implies$ $T: mathbb{R}^k to mathbb{R}^k$ Now since the matrix $A$ is invertible $implies$ $T$ has an inverse $T^{-1}$ $implies$ $T$ is injective thus the Null space $N(T)={0} implies $ $dim(N(T))=0$










share|cite|improve this question











$endgroup$




Let $A$ be an $m times n$ matrix of real numbers and $cl(A)$ denotes the column space of $A$, $R(A)$ denotes the row space of $A$ and $N(A)$ denotes the Null space of $A$.



I want to prove this statement.
If $m=n$ and $det(A) neq 0$ then $dim(N(A))=0$



My attempt.



An $m times n$ matrix of real numbers is a linear transformation $T: mathbb{R}^n to mathbb{R}^m$



let $m=n=k implies$ $T: mathbb{R}^k to mathbb{R}^k$ Now since the matrix $A$ is invertible $implies$ $T$ has an inverse $T^{-1}$ $implies$ $T$ is injective thus the Null space $N(T)={0} implies $ $dim(N(T))=0$







linear-algebra matrices proof-verification linear-transformations






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 22 '18 at 7:21









Shubham Johri

5,082717




5,082717










asked Dec 22 '18 at 7:03









Dreamer123Dreamer123

30429




30429








  • 1




    $begingroup$
    Your proof is correct. Was that your question?
    $endgroup$
    – Jonas
    Dec 22 '18 at 7:08










  • $begingroup$
    I am always suspicious if there is a mistake :)
    $endgroup$
    – Dreamer123
    Dec 22 '18 at 7:12






  • 1




    $begingroup$
    In future, use the proof-verification tag
    $endgroup$
    – Shubham Johri
    Dec 22 '18 at 7:20
















  • 1




    $begingroup$
    Your proof is correct. Was that your question?
    $endgroup$
    – Jonas
    Dec 22 '18 at 7:08










  • $begingroup$
    I am always suspicious if there is a mistake :)
    $endgroup$
    – Dreamer123
    Dec 22 '18 at 7:12






  • 1




    $begingroup$
    In future, use the proof-verification tag
    $endgroup$
    – Shubham Johri
    Dec 22 '18 at 7:20










1




1




$begingroup$
Your proof is correct. Was that your question?
$endgroup$
– Jonas
Dec 22 '18 at 7:08




$begingroup$
Your proof is correct. Was that your question?
$endgroup$
– Jonas
Dec 22 '18 at 7:08












$begingroup$
I am always suspicious if there is a mistake :)
$endgroup$
– Dreamer123
Dec 22 '18 at 7:12




$begingroup$
I am always suspicious if there is a mistake :)
$endgroup$
– Dreamer123
Dec 22 '18 at 7:12




1




1




$begingroup$
In future, use the proof-verification tag
$endgroup$
– Shubham Johri
Dec 22 '18 at 7:20






$begingroup$
In future, use the proof-verification tag
$endgroup$
– Shubham Johri
Dec 22 '18 at 7:20












0






active

oldest

votes











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
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3049181%2fdimension-of-the-null-space-of-an-invertible-square-matrix-a%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















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%2f3049181%2fdimension-of-the-null-space-of-an-invertible-square-matrix-a%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

Bressuire

Cabo Verde

Gyllenstierna