Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2010-03-19 23:45:06

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

Cute little problem I saw on another site



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

A: Click here for answer.

Offline

#2 2010-03-20 00:00:19

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

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.

Offline

#3 2010-03-22 18:37:04

scientia
Member
Registered: 2009-11-13
Posts: 222

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,

Offline

#4 2010-05-06 07:54:09

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

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 ∊ M[sub]n[/sub]


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

A: Click here for answer.

Offline

Board footer

Powered by FluxBB