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  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

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#1 2010-03-20 22:45:06

JaneFairfax
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Cute little problem I saw on another site







Q: Who wrote the novels Mrs Dalloway and To the Lighthouse?

A: Click here for answer.
 

#2 2010-03-20 23:00:19

mathsyperson
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Re: Cute little problem I saw on another site

Ah, now I see how this works. Nice puzzle.



Why did the vector cross the road?
It wanted to be normal.
 

#3 2010-03-23 17:37:04

scientia
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Re: Cute little problem I saw on another site


In general, for
, we have



This can be proved by induction. For the inductive step, note that







Hence, for this problem,

 

#4 2010-05-07 05:54:09

JaneFairfax
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Re: Cute little problem I saw on another site

scientia wrote:


In general, for
, we have

This is a very neat formula. It also proves that if



then −1 ∊ Mn


Q: Who wrote the novels Mrs Dalloway and To the Lighthouse?

A: Click here for answer.
 

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