This week we celebrated Euler’s birthday on 15th and I thought I need to write something about him. In my (almost) 4 years of university I have heard his name a lot of time. And this is a thing especially because at most of my courses the teachers don’t say anything about the mathematicians that worked at the things we see on the blackboard or in our notes. So here are a couple of things I have learned about Euler:
- we have to thank him for a couple of notations we use today: f(x) to denote the function f applied to the argument x; notation for the trigonometric functions; the Greek letter Σ for summations and the letter i to denote the imaginary unit.
- Euler’s number: the number e is an important mathematical constant that is the base of the natural logarithm; it is approximately equal to 2.71828. It has a lot of other incredible properties and you can find it almost everywhere in mathematics from calculus to number theory and probability.
- Euler’s formula: a mathematical formula in complex analysis that establishes the fundamental relationship between the trigonometric functions and the complex exponential function.
- Euler’s identity: mathematical beauty at its maximum and a combination of imaginary numbers, trigonometry and the number 0.