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Topic: My comments on "traditional" algorithms
Replies: 27   Last Post: Apr 13, 2000 9:25 PM

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Ted Alper

Posts: 118
Registered: 12/6/04
Re: My comments on "traditional" algorithms
Posted: Apr 6, 2000 1:05 PM
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>I came unstuck eventually when someone cleverly asked for 1.5245^20 (or
>something like that). I argued that this was unfair because it was really 19
>calculations but was howled down.


I'm coming to the discussion a bit late, but if you have your log
estimates memorized, you can do some reasonable approximations
here, too... but that just postpones the crash by one level of complexity.
Also the errors do multiply pretty quickly.

Let me see.... the only ones I remember off the top of my head is
ln(10) is pretty close to 2.3 also ln(3) is 1.099
and log-base-10 of 2 is .30103 (I like the palindrome, so I remembered it.
Also, I know 2^10 is a bit more than 10^3, which nails the relationship
down) ln(2) is a bit less than .7, but I don't remember the exact amount)


can I use those?
1.5245 is around 3/2, so ln(1.5245) must be a bit MORE than .399
times 20 must be about 8.. but what on earth is e^8? ln(10^3) is 6.9
ln(10^4) is 9.2, so it's somewhere in there... I need something with a ln
of 8 - 6.9... well, that sounds like 3 (quite close!)... so 3*1000 = 3000
is my estimate.

Phooey, I undershot by about 50%. Heck, most of the error comes from
replacing 1.5245 by 1.5, once you compound the error to the 20th power...
as an estimate for 1.5^20 I'm only off by around 10%.















Date Subject Author
3/31/00
Read My comments on "traditional" algorithms
Karen Dee Michalowicz
3/31/00
Read Re: My comments on "traditional" algorithms
MATH4FOBIX@aol.com
4/1/00
Read Re: My comments on "traditional" algorithms
CJ Masenas
4/1/00
Read Re: My comments on "traditional" algorithms
Ed Wall
4/2/00
Read Re: My comments on "traditional" algorithms
Joshua Zucker
4/4/00
Read Re: My comments on "traditional" algorithms
Joshua Zucker
4/4/00
Read Re: My comments on "traditional" algorithms
Ralph A. Raimi
4/4/00
Read Traditional Square-Root Algorithm
Guy Brandenburg
4/4/00
Read Re: Traditional Square-Root Algorithm
Bruce Balden
4/4/00
Read Re: Traditional Square-Root Algorithm
Ed Wall
4/4/00
Read Re: Traditional Square-Root Algorithm
Ralph A. Raimi
4/4/00
Read Re: Traditional Square-Root Algorithm
me@talmanl1.mscd.edu
4/6/00
Read Re: Traditional Square-Root Algorithm
me@talmanl1.mscd.edu
4/5/00
Read Re: My comments on "traditional" algorithms
Howard L. Hansen
4/5/00
Read Good books for smart high school students (was Re: My comments on
"traditional" algorithms)
Joshua Zucker
4/6/00
Read Good Books
Teague, Dan
4/8/00
Read RE: Good Books
Barron, Alfred [PRI]
4/8/00
Read Re: Good books for smart high school students (was Re: My comments
on"traditional" algorithms)
Gerald Von Korff
4/5/00
Read Re: My comments on "traditional" algorithms
Greg Goodknight
4/5/00
Read Re: My comments on "traditional" algorithms
Joshua Zucker
4/5/00
Read Re: My comments on "traditional" algorithms
Ralph A. Raimi
4/6/00
Read Re: My comments on "traditional" algorithms
rex@rocknet.net.au
4/6/00
Read Re: My comments on "traditional" algorithms
Ralph A. Raimi
4/6/00
Read Re: My comments on "traditional" algorithms
Ted Alper
4/6/00
Read Re: My comments on "traditional" algorithms
me@talmanl1.mscd.edu
4/6/00
Read Re: My comments on "traditional" algorithms
Ted Alper
4/10/00
Read Re: My comments on "traditional" algorithms
Sanjoy Mahajan
4/13/00
Read Reply to replies
Bonnie

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