How does the base e of natural logarithm come from?

As a mathematical constant, e is the basis of natural logarithmic function. Sometimes called Euler number, named after the Swiss mathematician Euler; There is also a relatively rare name, Napier constant, to commemorate the Scottish mathematician John? Napier introduced logarithm. It is one of the most important constants in mathematics, just like pi and imaginary units I and E.

Its numerical value is about (decimal point 100): e ≈ 2.7182818284 59045 23536 02874 71352 66249 77572 47093 6995 95749 66966.

The constant e was first developed by John? 16/kloc-a table in the appendix of napier's logarithmic works published in 0/8. But it does not record this constant, only a list of natural logarithms calculated from it, which is usually William? Made in William Oughtred. Is it the first time that Jacob regards e as a constant? Jacob Bernoulli.

The earliest known uses of the constant e are 1690 and 169 1 year, which is represented by B. In 1727, Euler began to use e to represent this constant. E was first used in publications, and it was Euler Mechanics in 1736. Although some researchers later used the letter C, E was widely used and finally became the standard.

The reason why E is used is really unknown, but it may be because E is the first letter of the word "index". Another view is that A, B, C and D have other common usages, and E is the first available letter. However, it is unlikely that Euler chose this letter because it is the initials of his own name, because he is a very modest person and always properly affirms the work of others.