Is this a typo in Section 1.8.1 Mathematics for Computer Science?How can I learn about proofs for computer science?How can I start to learn proof theory?Proving the existence of a proof without actually giving a proofProof by well ordering: Every positive integer greater than one can be factored as a product of primes.Gentzen and computer scienceElegant demonstration with minimum category theory knowledgeDifferent definitions of Natural Numbers and Proof by ContradictionProve $3^2n-5$ is a multiple of $4$Defining new symbols in a proof, when is this justified?Prove convergence rate to zero increases as n increases
How do I calculate how many of an item I'll have in this inventory system?
How to pass hash as password to ssh server
It is as simple as ABC
How do LIGO and VIRGO know that a gravitational wave has its origin in a neutron star or a black hole?
Should I simplify my writing in a foreign country?
Why do these characters still seem to be the same age after the events of Endgame?
Nested loops to process groups of pictures
Should I mention being denied entry to UK due to a confusion in my Visa and Ticket bookings?
Find magical solution to magical equation
Where are the "shires" in the UK?
Install LibreOffice-Writer Only not LibreOffice whole package
Dihedral group D4 composition with custom labels
Constitutional limitation of criminalizing behavior in US law?
Does XQuartz work on macOS Mojave?
History of the kernel of a homomorphism?
Why doesn't ever smooth vector bundle admits a line bundle?
Hostile Divisor Numbers
Can I use a Cat5e cable with an RJ45 and Cat6 port?
Is an HNN extension of a virtually torsion-free group virtually torsion-free?
Why would a military not separate its forces into different branches?
Is the book wrong about the Nyquist Sampling Criterion?
Is there an age requirement to play in Adventurers League?
Why does sound not move through a wall?
SOQL query WHERE filter by specific months
Is this a typo in Section 1.8.1 Mathematics for Computer Science?
How can I learn about proofs for computer science?How can I start to learn proof theory?Proving the existence of a proof without actually giving a proofProof by well ordering: Every positive integer greater than one can be factored as a product of primes.Gentzen and computer scienceElegant demonstration with minimum category theory knowledgeDifferent definitions of Natural Numbers and Proof by ContradictionProve $3^2n-5$ is a multiple of $4$Defining new symbols in a proof, when is this justified?Prove convergence rate to zero increases as n increases
$begingroup$
Am I completely mistake or is it suppose to say $n^2$ is a multiple of 2 and therefore $n$ must be a multiple of 4?
This is from MIT's Mathematics for Computer Science
proof-explanation proof-theory
$endgroup$
add a comment |
$begingroup$
Am I completely mistake or is it suppose to say $n^2$ is a multiple of 2 and therefore $n$ must be a multiple of 4?
This is from MIT's Mathematics for Computer Science
proof-explanation proof-theory
$endgroup$
$begingroup$
Generally: If $m,n$ are positive integers and $m^1/n$ is not an integer then $m^1/n$ is irrational. Proved by a similar method.
$endgroup$
– DanielWainfleet
Apr 26 at 1:48
1
$begingroup$
What makes you think this is a mistake?
$endgroup$
– Servaes
Apr 26 at 7:31
add a comment |
$begingroup$
Am I completely mistake or is it suppose to say $n^2$ is a multiple of 2 and therefore $n$ must be a multiple of 4?
This is from MIT's Mathematics for Computer Science
proof-explanation proof-theory
$endgroup$
Am I completely mistake or is it suppose to say $n^2$ is a multiple of 2 and therefore $n$ must be a multiple of 4?
This is from MIT's Mathematics for Computer Science
proof-explanation proof-theory
proof-explanation proof-theory
asked Apr 26 at 1:14
doctopusdoctopus
1414
1414
$begingroup$
Generally: If $m,n$ are positive integers and $m^1/n$ is not an integer then $m^1/n$ is irrational. Proved by a similar method.
$endgroup$
– DanielWainfleet
Apr 26 at 1:48
1
$begingroup$
What makes you think this is a mistake?
$endgroup$
– Servaes
Apr 26 at 7:31
add a comment |
$begingroup$
Generally: If $m,n$ are positive integers and $m^1/n$ is not an integer then $m^1/n$ is irrational. Proved by a similar method.
$endgroup$
– DanielWainfleet
Apr 26 at 1:48
1
$begingroup$
What makes you think this is a mistake?
$endgroup$
– Servaes
Apr 26 at 7:31
$begingroup$
Generally: If $m,n$ are positive integers and $m^1/n$ is not an integer then $m^1/n$ is irrational. Proved by a similar method.
$endgroup$
– DanielWainfleet
Apr 26 at 1:48
$begingroup$
Generally: If $m,n$ are positive integers and $m^1/n$ is not an integer then $m^1/n$ is irrational. Proved by a similar method.
$endgroup$
– DanielWainfleet
Apr 26 at 1:48
1
1
$begingroup$
What makes you think this is a mistake?
$endgroup$
– Servaes
Apr 26 at 7:31
$begingroup$
What makes you think this is a mistake?
$endgroup$
– Servaes
Apr 26 at 7:31
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
No, it is correct. The point is that $2d^2=n^2$ implies $n^2$ is even, and only even numbers square to give an even number, so $n$ much be even, so $n^2$ is then actually a multiple of $4$.
$endgroup$
$begingroup$
This makes sense thanks
$endgroup$
– doctopus
2 days ago
add a comment |
$begingroup$
No. $6^2$ is a multiple of $2$ but $6$ is not a multiple of $4$. If $n=2k$ then for sure $n^2=4k^2$. So, MIT is right.
$endgroup$
add a comment |
Your Answer
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%2f3202666%2fis-this-a-typo-in-section-1-8-1-mathematics-for-computer-science%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
No, it is correct. The point is that $2d^2=n^2$ implies $n^2$ is even, and only even numbers square to give an even number, so $n$ much be even, so $n^2$ is then actually a multiple of $4$.
$endgroup$
$begingroup$
This makes sense thanks
$endgroup$
– doctopus
2 days ago
add a comment |
$begingroup$
No, it is correct. The point is that $2d^2=n^2$ implies $n^2$ is even, and only even numbers square to give an even number, so $n$ much be even, so $n^2$ is then actually a multiple of $4$.
$endgroup$
$begingroup$
This makes sense thanks
$endgroup$
– doctopus
2 days ago
add a comment |
$begingroup$
No, it is correct. The point is that $2d^2=n^2$ implies $n^2$ is even, and only even numbers square to give an even number, so $n$ much be even, so $n^2$ is then actually a multiple of $4$.
$endgroup$
No, it is correct. The point is that $2d^2=n^2$ implies $n^2$ is even, and only even numbers square to give an even number, so $n$ much be even, so $n^2$ is then actually a multiple of $4$.
answered Apr 26 at 1:21
John DoeJohn Doe
12.6k11441
12.6k11441
$begingroup$
This makes sense thanks
$endgroup$
– doctopus
2 days ago
add a comment |
$begingroup$
This makes sense thanks
$endgroup$
– doctopus
2 days ago
$begingroup$
This makes sense thanks
$endgroup$
– doctopus
2 days ago
$begingroup$
This makes sense thanks
$endgroup$
– doctopus
2 days ago
add a comment |
$begingroup$
No. $6^2$ is a multiple of $2$ but $6$ is not a multiple of $4$. If $n=2k$ then for sure $n^2=4k^2$. So, MIT is right.
$endgroup$
add a comment |
$begingroup$
No. $6^2$ is a multiple of $2$ but $6$ is not a multiple of $4$. If $n=2k$ then for sure $n^2=4k^2$. So, MIT is right.
$endgroup$
add a comment |
$begingroup$
No. $6^2$ is a multiple of $2$ but $6$ is not a multiple of $4$. If $n=2k$ then for sure $n^2=4k^2$. So, MIT is right.
$endgroup$
No. $6^2$ is a multiple of $2$ but $6$ is not a multiple of $4$. If $n=2k$ then for sure $n^2=4k^2$. So, MIT is right.
answered Apr 26 at 1:19
RandallRandall
10.9k11431
10.9k11431
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%2f3202666%2fis-this-a-typo-in-section-1-8-1-mathematics-for-computer-science%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
$begingroup$
Generally: If $m,n$ are positive integers and $m^1/n$ is not an integer then $m^1/n$ is irrational. Proved by a similar method.
$endgroup$
– DanielWainfleet
Apr 26 at 1:48
1
$begingroup$
What makes you think this is a mistake?
$endgroup$
– Servaes
Apr 26 at 7:31