A-Level Maths: A1-07 [Proof by Deduction Examples]

[eesaarashid]

This teacher is so good. Honestly your a great help man.

[freerights]

I understand the reasoning and the logic behind every step you take. I just don't get how you come up with things like (k-1) * k * (k+1) and think of them as consecutive numbers, where atleast one will be even, and another a multiple of 3. Maybe I just don't think in the right way, but I can't come up with these answers myself, though it makes a lot of sense when you go through them.

[Quoii]

You are seriously an amazing teacher. Each day my confidence in maths improves by watching your videos! Many thanks :)

[kamrangraves]

ur actually the best maths youtuber out there

[adamburgess]

Thank you for the videos they're great.

[graydiation]

Thank you from 2019. Why wouldn't someone not give in Algebraic explanation, whenever the mathematical problem isn't simple?

[adamtaylor]

I thought I would never understand this topic but this video helped a lot, thank you

[au]

I'm a little confused to how you got the 5n when expanding the brackets. I have clearly missed something. Could you please explain if possible :)

[treesattheriver]

Very clear explaination and easy to understand even a difficult questions

[samirihamk]

for the second example: so we dont have to worry about the k>1 in our working?? cos some questions need you to think about it to get your answer and others dont, so im just confused on when i do or dont need to look at and worry about it. Great video by the way, thankyouu

[AceOfHearts]

Jack thanks found Q2 helpful... was wondering why if we try proof by exhaustion does not work with k equals 2n+1 and 2n

[aminarabbagheri]

Example 2, why k>1 as k=0 or k=1 won't contradict the conjecture?

[noahsteele]

for 2nd example, why must it be divisible by 2? if there are 2 evens then it wont be? (eg 4+5+6 = 15)

[artloverrarts]

thank you so much, I really needed this

[AshBeastFPS]

Thanks, I understand the first one, but the second question went over my head, gonna rewatch it but if you can help me Jack, I would appreciate it.

[Oh-lkqd]

Hi sir with the second example I set the k as (n^2+1) because it has to be greater than 1 and also positive but when I did the full expansion I got n^6+ 3n^4+ 2n^2. Have I expanded it wrong our is there a way to show that that's divisible by 6?

[extremegamer]

You know for the second example. Cant you use a value greater than 1 for K and prove it this way?

[moushwuzhere]

For the first one is it possible to use 4n-4 4n-3 4n-2 4n-1?

[qaasimcabdi]

Where does the year one content end and the year two content start

[jadiewadie]

how, in the first one, is 5n - -n = 4n? wouldnt it be 6n?