Proof by Contradiction | Method & First Example

Proof by Contradiction is one of the most important proof methods. It is an indirect proof technique that works like this: You want to show a statement P is true. First assume the P is actually false. Then manipulate until you get a contradiction like 0=1. This means your assumption that P was false is incorrect and so P is true. QED.

In this video we'll talk about the structure of proof by contradiction, and then do a small example where we prove a theorem that no integer is both even and odd.

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[SaucyRamenBoy]

im not sure what to be more impressed by, how clearly he explained this in 9 minutes or the fact that he can write in reverse and make it look good

[rajdeepchakraborty]

The contradiction (k1-k2) being 1/2 was such a subtle and beautiful point!

[PLP]

Ah yes. Graduated a few years ago with my math degree but still come here to pay homage. Thanks!

[catherinedinh]

deadass you cleared up every question i had about this concept within the first two minutes. ur an amazing teacher

[markjoshuaobial]

I don't know what's the reason but this video helps me more in understanding the lesson than my professor teaching this topic. Thank you for this educational video!

[didierliango]

So beautifully explained. In grade 8, my mathematics teacher introduced us to this proof my absurdity for the first time.. and he was fascinated by it so much that i also fell in love with this technique.

[ro-cevg]

the videos my university class provides me are absolutely mind numbing, it goes such a long way to have someone energetic on the screen explaining this stuff

[YeabsiraHenok]

Thank you Dr. Trefor Bazett and I am really enjoying your DIFFERENTIAL EQUATIONS playlist as well.

[おりおり-hl]

I really love your video, like it's way easier to understand than my prof's lecture tbh...

I kind of get how to USE all the proof methods, but how do people know which one to use for each problem??? Practice?

[GudyaRawat]

Your explanation is appreciated by all. Love from India❤

[Jaffy.]

I sense both teaching skill and passion

[Nelsonoliva]

Bro taught me in 9 minutes what my professor just yapped from the slides for 2 hours. MVP

[abbassharbi]

i swear from morning i watch a videos but i didn't understand any thing till i found you best dr. for ever from now i am one of your subscribers💌

[avarokinraj]

This is so trippy! He's writing in reverse!

[inquisitive]

This guy is the PatrickJMT of higher level math.

[patrickmayer]

Perfect example to explain the topic! Thanks for the video, Dr. Bazett!

[benkozireski]

I must say you are so dedicated to these videos that you write in reverse! well done

[deadbitehu]

Thanks my teachers goes way to fast and messes up a lot. This made it clear

[student]

thanks for this...its helpin me for my exam preparation

[TitanTubs]

Dang man, they are still releasing DLC's for math? How much longer are they going to add to this?
I miss the old 1+3=4 game.