The first mention of the constant e is a table in the appendix of John Napier's logarithmic works published in 16 18. But it didn't record this constant, only a list of natural logarithms calculated from it, which is generally believed to be made by William Oughtred. It was Jacob Bernoulli who first thought that E was a constant.

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.

Extended data

E was not originally found in nature, but related to the compound interest of banks.

Imagine that if you put your money in a bank, the annual interest rate is 100%, and after one year, the money will increase to (1+ 1) 1 = 2 times. If the bank does not settle interest in this way, but calculates it every six months, but the interest rate for half a year is 50% of the previous annual interest rate, then the money will increase to (1+0.5) 2 = 2.25 times after one year.

Similarly, if the daily interest rate is 1/365, the money will increase to (1+1/365) 365 ≈ 2.71times after one year.

Baidu encyclopedia -e