Prove that if $m, n, dinmathbb{Z^+}$ and $d | m^2n+1, d | mn^2+1$ then $d | m^3+1, d | n^3+1$
$begingroup$
Prove that if $m, n, dinmathbb{Z^+}$ and $d | m^2n+1, d | mn^2+1$ then $d | m^3+1, d | n^3+1$
My attempt:
So I said that from this we can safely say that
$$m^2nequiv-1pmod{d}, mn^2equiv-1pmod{d}$$
This means that:
$$mn(m)equiv mn(n)pmod{d}$$
Now if $gcd(mn, d)=1$ then we will get that
$$mequiv{n}pmod{d}$$
Now in our original equation we will get
$$m^2n+1equiv0pmod{d}, mn^2+1equiv0pmod{d}$$
$$therefore m^3+1equiv0pmod{d}, n^3+1equiv0pmod{d}$$
But what if $gcd(mn,d)gt{1}$, what will I have to do? And is that even possible in the first place? Thank you in advance.
elementary-number-theory
$endgroup$
add a comment |
$begingroup$
Prove that if $m, n, dinmathbb{Z^+}$ and $d | m^2n+1, d | mn^2+1$ then $d | m^3+1, d | n^3+1$
My attempt:
So I said that from this we can safely say that
$$m^2nequiv-1pmod{d}, mn^2equiv-1pmod{d}$$
This means that:
$$mn(m)equiv mn(n)pmod{d}$$
Now if $gcd(mn, d)=1$ then we will get that
$$mequiv{n}pmod{d}$$
Now in our original equation we will get
$$m^2n+1equiv0pmod{d}, mn^2+1equiv0pmod{d}$$
$$therefore m^3+1equiv0pmod{d}, n^3+1equiv0pmod{d}$$
But what if $gcd(mn,d)gt{1}$, what will I have to do? And is that even possible in the first place? Thank you in advance.
elementary-number-theory
$endgroup$
add a comment |
$begingroup$
Prove that if $m, n, dinmathbb{Z^+}$ and $d | m^2n+1, d | mn^2+1$ then $d | m^3+1, d | n^3+1$
My attempt:
So I said that from this we can safely say that
$$m^2nequiv-1pmod{d}, mn^2equiv-1pmod{d}$$
This means that:
$$mn(m)equiv mn(n)pmod{d}$$
Now if $gcd(mn, d)=1$ then we will get that
$$mequiv{n}pmod{d}$$
Now in our original equation we will get
$$m^2n+1equiv0pmod{d}, mn^2+1equiv0pmod{d}$$
$$therefore m^3+1equiv0pmod{d}, n^3+1equiv0pmod{d}$$
But what if $gcd(mn,d)gt{1}$, what will I have to do? And is that even possible in the first place? Thank you in advance.
elementary-number-theory
$endgroup$
Prove that if $m, n, dinmathbb{Z^+}$ and $d | m^2n+1, d | mn^2+1$ then $d | m^3+1, d | n^3+1$
My attempt:
So I said that from this we can safely say that
$$m^2nequiv-1pmod{d}, mn^2equiv-1pmod{d}$$
This means that:
$$mn(m)equiv mn(n)pmod{d}$$
Now if $gcd(mn, d)=1$ then we will get that
$$mequiv{n}pmod{d}$$
Now in our original equation we will get
$$m^2n+1equiv0pmod{d}, mn^2+1equiv0pmod{d}$$
$$therefore m^3+1equiv0pmod{d}, n^3+1equiv0pmod{d}$$
But what if $gcd(mn,d)gt{1}$, what will I have to do? And is that even possible in the first place? Thank you in advance.
elementary-number-theory
elementary-number-theory
asked Dec 15 '18 at 4:22
user587054user587054
46511
46511
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Let $p$ be any prime divisor of $d$, and let $k$ be the maximum natural number such that $p^k mid d$. Observe that: $p^k mid d mid mn(m-n)$, and $m^2n+1 = m^2(n-m+m)+1 = m^3+1 + (n-m)m^2$. This means that if $p^k nmid (n-m)implies p^k mid mnimplies p mid 1$, contradiction $p$ being a prime. Thus $p^k mid (n-m)$,and this means $p^k mid m^3+1$. Thus $d mid (m^3+1)$, and similarly $d mid (n^3+1)$. Note that if $p^r mid (n-m)$, and $p^s mid mn$ with $r+s = k$, then $p mid m^2n implies p mid 1$, contradiction $p$ being a prime.
$endgroup$
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%2f3040168%2fprove-that-if-m-n-d-in-mathbbz-and-d-m2n1-d-mn21-then-d-m%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
$begingroup$
Let $p$ be any prime divisor of $d$, and let $k$ be the maximum natural number such that $p^k mid d$. Observe that: $p^k mid d mid mn(m-n)$, and $m^2n+1 = m^2(n-m+m)+1 = m^3+1 + (n-m)m^2$. This means that if $p^k nmid (n-m)implies p^k mid mnimplies p mid 1$, contradiction $p$ being a prime. Thus $p^k mid (n-m)$,and this means $p^k mid m^3+1$. Thus $d mid (m^3+1)$, and similarly $d mid (n^3+1)$. Note that if $p^r mid (n-m)$, and $p^s mid mn$ with $r+s = k$, then $p mid m^2n implies p mid 1$, contradiction $p$ being a prime.
$endgroup$
add a comment |
$begingroup$
Let $p$ be any prime divisor of $d$, and let $k$ be the maximum natural number such that $p^k mid d$. Observe that: $p^k mid d mid mn(m-n)$, and $m^2n+1 = m^2(n-m+m)+1 = m^3+1 + (n-m)m^2$. This means that if $p^k nmid (n-m)implies p^k mid mnimplies p mid 1$, contradiction $p$ being a prime. Thus $p^k mid (n-m)$,and this means $p^k mid m^3+1$. Thus $d mid (m^3+1)$, and similarly $d mid (n^3+1)$. Note that if $p^r mid (n-m)$, and $p^s mid mn$ with $r+s = k$, then $p mid m^2n implies p mid 1$, contradiction $p$ being a prime.
$endgroup$
add a comment |
$begingroup$
Let $p$ be any prime divisor of $d$, and let $k$ be the maximum natural number such that $p^k mid d$. Observe that: $p^k mid d mid mn(m-n)$, and $m^2n+1 = m^2(n-m+m)+1 = m^3+1 + (n-m)m^2$. This means that if $p^k nmid (n-m)implies p^k mid mnimplies p mid 1$, contradiction $p$ being a prime. Thus $p^k mid (n-m)$,and this means $p^k mid m^3+1$. Thus $d mid (m^3+1)$, and similarly $d mid (n^3+1)$. Note that if $p^r mid (n-m)$, and $p^s mid mn$ with $r+s = k$, then $p mid m^2n implies p mid 1$, contradiction $p$ being a prime.
$endgroup$
Let $p$ be any prime divisor of $d$, and let $k$ be the maximum natural number such that $p^k mid d$. Observe that: $p^k mid d mid mn(m-n)$, and $m^2n+1 = m^2(n-m+m)+1 = m^3+1 + (n-m)m^2$. This means that if $p^k nmid (n-m)implies p^k mid mnimplies p mid 1$, contradiction $p$ being a prime. Thus $p^k mid (n-m)$,and this means $p^k mid m^3+1$. Thus $d mid (m^3+1)$, and similarly $d mid (n^3+1)$. Note that if $p^r mid (n-m)$, and $p^s mid mn$ with $r+s = k$, then $p mid m^2n implies p mid 1$, contradiction $p$ being a prime.
answered Dec 15 '18 at 5:10
DeepSeaDeepSea
70.9k54487
70.9k54487
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%2f3040168%2fprove-that-if-m-n-d-in-mathbbz-and-d-m2n1-d-mn21-then-d-m%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