
Dictionary » L » Logarithm LogarithmLogarithm (Science: mathematics) One of a class of auxiliary numbers, devised by john napier, of Merchiston, Scotland (15501617), to abridge arithmetical calculations, by the use of addition and subtraction in Place of multiplication and division. The relation of logarithms to common numbers is that of numbers in an arithmetical series to corresponding numbers in a geometrical series, so that sums and differences of the former indicate respectively products and quotients of the latter; thus 0 1 2 3 4 indices or logarithms 1 10 100 1000 10,000 numbers in geometrical progression Hence, the logarithm of any given number is the exponent of a power to which another given invariable number, called the base, must be raised in order to produce that given number. Thus, let 10 be the base, then 2 is the logarithm of 100, because 10^2 = 100, and 3 is the logarithm of 1,000, because 10^3 = 1,000. Arithmetical complement of a logarithm, the difference between a logarithm and the number ten. Binary logarithms. See binary. Common logarithms, or Brigg's logarithms, logarithms of which the base is 10; so called from henry Briggs, who invented them. Gauss's logarithms, tables of logarithms constructed for facilitating the operation of finding the logarithm of the sum of difference of two quantities from the logarithms of the quantities, one entry of those tables and two additions or subtractions answering the purpose of three entries of the common tables and one addition or subtraction. They were suggested by the celebrated german mathematician Karl Friedrich gauss (died in 1855), and are of great service in many astronomical computations. Hyperbolic, or Napierian, logarithms, those logarithms (devised by john Speidell, 1619) of which the base is 2.7182818; so called from napier, the inventor of logarithms. Logistic or Proportionallogarithms. Origin: gr. Word, account, proportion _ number: cf. F. Logarithme. Please contribute to this project, if you have more information about this term feel free to edit this page Results from our forumratio of product / reactantLog is a logarithm: explanation in wikipedia: http://en.wikipedia.org/wiki/Logarithm basic maths skills are useful in biology, you know?
See entire post
change in free energy equationLOG is a mathematical operation. In this case it is the Decimal logarithm (sometimes abbreviated as Log10), not the natural logarithm (generally abbreviated as Ln). It means that 10^(0.5501)=0.2818 It is quite hard to calculate in your head, or even on ...
See entire post
ratio of product / reactantLOL, that's all what you need? Just convert logarithm to normal number? log (10^x) = x ^ here means power, so you can have like: log 100 = log (10^2) = 2 pretty simple, isn't it? (of course, this is decimal logarithm, but the basis can be any)
See entire post
Doubling time for cells... : c1 Let them grow during h hours Count them again : c2 The doubling time(in hours)=h*ln(2)/ln(c2/c1) You can use decimal or neperien logarithm. You can use this formula to forcast the cell expension or to calculate the volume to split to get a target concentration after a period of ...
See entire post
Finding RF?the distance a molecule travels in a gel is inversely proportional to the logarithm of the molecular weight. > so you can plot a curve where distance is set out against the logarithm of the molecular weigth and you will get a straight line.
See entire post
This page was last modified 21:16, 3 October 2005. This page has been accessed 3,628 times. 
© BiologyOnline.org. All Rights Reserved.
Register  Login
 About Us  Contact Us  Link to Us  Disclaimer & Privacy  Powered by CASPION