Leonhard Euler

Leonhard Euler (German: Leonhard Euler, April 15, 1707 - September 18, 1783), Swiss mathematician, physicist, astronomer, geographer, logician and engineer. Euler made significant contributions to many areas of mathematics, including calculus and graph theory. He introduced and popularized many mathematical terms and writing formats that are still in use today, such as the notation of functions f ( x ) {\displaystyle f(x)} , imaginary unit − 1 {\displaystyle {\sqrt {-1}}} notation i {\displaystyle i} , the notation of pi π {\displaystyle \pi } (This notation was originally derived from William Jones), the summation symbol Σ {\displaystyle \Sigma } , differential sign Δ {\displaystyle \Delta } As well as using lowercase letters to represent the sides of a triangle and using uppercase letters to represent the angles of a triangle, etc. The base of the natural logarithm is also given e {\displaystyle e} Definition, which is also called Euler’s number (Euler