#1047
готов
 2019-05-09 22:14 ..... Karasick 2019-05-08 23:28 .......... Max 2018-08-31 12:00 ... GOOGLE.COM пустая запись Approximations A table of slightly wrong equations and identities useful for approximations and or trolling teachers. (Found using a mix of trial-and-error, Mathematica, and Robert Munafo's Ries tool.) All units are SI MKS unless otherwise noted. Relation: One light year(m) ~= 99^8 Accurate to within: one part in 40 Relation: Earth Surface(m^2) ~= 69^8 Accurate to within: one part in 130 Relation: Ocean's volume(m^3) ~= 9^19 Accurate to within: one part in 70 Relation: Seconds in a year ~= 75^4 Accurate to within: one part in 400 Relation: Seconds in a year (rent method) ~= 525,600 x 60 Accurate to within: one part in 1400 Relation: Age of the universe (seconds) ~= 15^15 Accurate to within: one part in 70 Relation: Planck's constant ~= 1 (30^pi^e) Accurate to within: one part in 110 Relation: Fine structure constant ~= 1 140 Accurate to within: [I've had enough of this 137 crap] Relation: Fundamental charge ~= 3 (14 * pi^pi^pi) Accurate to within: one part in 500 Relation: White House Switchboard ~= 1 (e^(1+(8)^(1 (e-1)^(1 pi) Relation: Jenny's Constant ~= (7^(e 1- 1 e) - 9) * pi^2 Intermission: World Population Estimate which should stay current for a decade or two: Take the last two digits of the current year Example: 20[14] Subtract the number of leap years since hurricane Katrina Example:14 (minus 2008 and 2012) is 12 Add a decimal point Example: 1.2 Add 6 Example: 6 + 1.2 7.2 ~= World population in billions. Version for US population: Example: 20[14] Subtract 10 Example: 4 Multiply by 3 Example: 12 Add 10 Example: 3[22] million Relation: Electron rest energy ~= e 7^16 Joules Accurate to within: one part in 1000 Relation: Light-year(miles) ~= 2^42.42 Accurate to within: one part in 1000 Relation: sin(60 degrees) = (3^(1 2) 2 ~= e pi Accurate to within: one part in 1000 Relation: (3)^(1 2) ~= 2e pi Accurate to within: one part in 1000 Relation: gamma(Euler's gamma constant) ~= 1 (3^(1 2) Accurate to within: One part in 4000 Relation: Feet in a meter ~= 5 (pi^(1 e) Accurate to within: one part in 4000 Relation: (5)^(1 2) ~= 2 e + 3 2 Accurate to within: one part in 7000 Relation: Avogadro's number ~= 69^pi^5^(1 2) Accurate to within: one part in 25,000 Relation: R(gas constant) ~= (e+1) * (5^(1 2) Accurate to within: one part in 50,000 Relation: Proton-electron mass ratio ~= 6*pi^5 Accurate to within: one part in 50,000 Relation: Liters in a gallon ~= 3+pi 4 Accurate to within: one part in 500,000 Relation: g ~= 6+ln(45) Accurate to within: one part in 750,000 Relation: Proton-electron mass ratio ~= (e^8 -10) phi Accurate to within: one part in 5,000,000 Relation: Ruby laser wavelength ~= 1 1200^2 Accurate to within: [within actual variation] Relation: Mean Earth Radius ~= (5^8)*6e Accurate to within: [within actual variation] Protip - not all of these are wrong: 2^(1 2) ~= 3 5+pi (7-pi) cos(pi 7) + cos(3pi 7) + cos(5pi 7) ~= 1 2 gamma(Euler's gamma constant) ~= e 3^4 + e 5 5^(1 2) ~= (13 + 4pi) (24 - 4pi) sigma(1 n^n) ~= ln(3)^e Two tips: 1) 8675309 is not just prime, it's a twin prime, and 2) if you ever find yourself raising log(anything)^e or taking the pi-th root of anything, set down the marker and back away from the whiteboard; something has gone horribly wrong.