A-Level Maths: A1-13 Proving √3 is Irrational - Alternative Method

[allie]

was struggling with this proof in my class today (prof wrote down a series of steps without any explanation), however this video makes it so easy to understand! so thanks!

[talharandhawarandhawa]

This explanation is far better than my textbook

[nirmalupadhyay]

BLESSINGS FROM INDIA GUJARAT SIR GOD BLESS U SIR RADHEY RADHEY SIR 🙏🏻🙏🏻🙏🏻🙏🏻🙏🏻🙏🏻🙏🏻🙏🏻

[HaNaMaiLa.]

I just stumbled on your channel minute ago, and I've subscribed 😊
Hope to learn more

[faisca]

Thank you for this beautiful proof and for your excellent explanation!

[hgc]

This proof is beautiful. Thank very much!

[novanerd]

so i followed your guide and got the question in a test paper i did exactly what you did but was marked wrong was wondering if there are any other methods as i lost 6 marks on this question and i am frustrated as i keep thinking i should of got this question correct. I do Edexcel.

[jayadenuja]

Why can’t we say both a and b can’t both be multiples of 3 (otherwise they weren’t simplified). If 3b^2= a^2 then a^2 is a multiple of three and if that’s the case, a is also a multiple of 3. A=3k, 3b^2=9k^2 so b must also be a multiple of 3.

[hoyama]

can we use the same method that we used to prove that root 2 is irrational?

[babss]

(2n+1)^2 does not = 4n^2+4n but rather 4n^2+4n+1?

[kaijss]

I do edexcel. Can they ask us to prove anything by contradiction or just the examples stated in the spec?

[hairyarms]

Why not just use the root 2 method and use "divisible by 3 " instead of "even"

[thesudaneseprince]

Thank you for these videos they are extremely useful, however, I just as a year 11 going into A-level maths cannot understand how you would know what to do, like I understand the maths, but is there a methodology to this proof, I got up to 3b^2 = a^2 using what I learned from the "proving root 2 is irrational video" but then I was stumped how did you know to start experimenting with odds and evens. Did you just look at the success criteria (a and b cannot be even) and use that as a launchpad for your proof?

Many thanks in advance,

[eyefeelpineal]

Hello,
From the 3(2m + 1)² ...
I understand how you got the 12m² and the 3, but I don't see how you got the 12m?

[pranavkarna]

If both is not even that doesn't mean it is in simplest form, let one is even 6 and one is odd 9 it is also not in simplest form

[headieoneee]

Why couldn’t you at the end just say odd=even because even + 1 is odd therefore that’s wrong because it proves the assumption right

[edwardhudson]

it doesn't take 10 minutes lol. just type root 3 into your caculator

[madk]

The shittest explanation known to man^^!! He gave up and just says then here is your contradiction.