Re: Re: Magic number 23
- To: mathgroup at smc.vnet.net
- Subject: [mg41488] Re: [mg41466] Re: Magic number 23
- From: David Terr <dterr at wolfram.com>
- Date: Thu, 22 May 2003 06:55:23 -0400 (EDT)
- References: <baclk4$r54$1@smc.vnet.net> <200305211201.IAA06871@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Dave Langers wrote: >>Mathematica knows the exact values of the trigonometric functions for some >>special angles. I was curious how many such values there are. >> > >Take a look at: >http://mathworld.wolfram.com/TrigonometricAngles.html > >It doesn't explain what might be special about sin(pi/23), except that >it cannot be written as a simple exact value. > >BTW: This is interestingly enough related to constructions with compass >and straightedge: >http://mathworld.wolfram.com/ConstructibleNumber.html >http://mathworld.wolfram.com/ConstructiblePolygon.html > >Greetings, >Dave > > 23 is magic in the sense it's the smallest positive number n such that sin(pi/n) is not solvable with radicals. To get radical expressions for smaller values of n, use FunctionExpand. David
- References:
- Re: Magic number 23
- From: Dave Langers <RemoveThisPart.d.langers@wxs.nl>
- Re: Magic number 23