Wikipedia:Reference desk/Archives/Mathematics/2018 July 11

= July 11 =

About the logarithmics
I want to learn logarithmic from basic suggest me good mathematics online training institute. and i want some tricks to remember numbers such as logs of numbers, squares and cubes of large numbers — Preceding unsigned comment added by 117.192.97.185 (talk) 11:50, 11 July 2018 (UTC)
 * Hi, a good starting point to learn about Logarithms is the Wikipedia article about them. If you have any specific questions about logarithms, or any other mathematical query, feel free to ask here for assistance. Iffy★Chat -- 12:00, 11 July 2018 (UTC)
 * This article in Simple Wikipedia may help. DroneB (talk) 00:45, 15 July 2018 (UTC)

Some tricks to remember logs of numbers
Musicians call the unit of the base 2 logarithm: the octave, because the double frequency is the eighth tone, counting from one. So 7 tone-intervals make one octave-interval. A tripling is approximately the duodecim, equal to 11 tones.
 * 2 = 7 tones
 * 3 = 11 tones.

This is all you need to remember! Then compute 4 = 14 tones (7+7). 6 = 18 tones (7+11). 8 = 21 tones (7+7+7). 9 = 22 tones (11+11). The intermediate numbers have intermediate logarithms: 5 = 16 tones (between 14 and 18). 7 = 19½ tones(between 18 and 21). 10 = 23 tones (7+16). So on the back of an envelope you construct this rude table of logarithms. 1   2    3    4    5    6    7    8    9   10   0    7   11   14   16   18   19   21   22   23 These numbers happen to be ten times the natural logarithm. So the unit of natural logarithm is 10 tones. Bo Jacoby (talk) 12:57, 15 July 2018 (UTC).

You can get a good feeling for logarithms by playing with a slide rule if you can still find one. 173.228.123.166 (talk) 02:56, 16 July 2018 (UTC)

Unistable polyhedrons
Talk:Monostatic polytope

--CiaPan (talk) 14:29, 11 July 2018 (UTC)
 * The 1959 date seems to be a typo, which I'll go ahead and fix. It may be hard to determine which contributions were Guy's and which Conway's, but it looks like Guy invented the specific polyhedron while they both coauthored the paper (actually it's just a problem) in which it's described. --RDBury (talk) 01:48, 12 July 2018 (UTC)


 * See youtube https://www.youtube.com/watch?v=9_EK4ki2_Yk -- SGBailey (talk) 22:12, 13 July 2018 (UTC)