Method isn't really deduction is it, because your exhausting all integer as they can take the 3n+1.3n+2,3n values. So its proof by exhaustion as your exhausting all the values the integers can take
The 2nd question is wrong as 1 cubed can not be a mulitple of 9. Therefore the question is only valid for positive integers greater than or equal to 2. That is why you have to use 3n
Sorry if this sounds ignorant as im not too great at maths right now, just finished gcse's and trying to learn a level maths. Would 1 not be (9x0) + 1 which is still a multiple of 9 +1?
Why do we use 3n? Can we use n instead as well?
how would you know in an exam though to use (3n)^3 and not just n^3 (which was my first instinct when I read part 2)
The other channel he explains this from @3:30
Hi Can you also use 3x+1 instead of 3x-2 ?
Yeah you can
Very nice presentation indeed! Thank you!
Thanks for watching.
great vid!!! ohh and there’s a minor error on the (3n-1)^3 . It would be 9 (3n^3 +3n^2 +n)-1 not “plus 1”
Oops! Thanks for pointing that out. Will try to change at some point.
Method isn't really deduction is it, because your exhausting all integer as they can take the 3n+1.3n+2,3n values. So its proof by exhaustion as your exhausting all the values the integers can take
is this in maths edexcel A level??
The new spec
thanks
The 2nd question is wrong as 1 cubed can not be a mulitple of 9. Therefore the question is only valid for positive integers greater than or equal to 2. That is why you have to use 3n
Thanks for pointing this out, you are quite right. My mistake.
Sorry if this sounds ignorant as im not too great at maths right now, just finished gcse's and trying to learn a level maths. Would 1 not be (9x0) + 1 which is still a multiple of 9 +1?