# Euler, Leonhard

### (1707-1783)

The greatest mathematician of the eighteenth century, Leonhard Euler was born in Basel, Switzerland. There, he studied under another giant of mathematics, Jean Bernoulli. In 1731 Euler became a professor of physics and mathematics at St. Petersburg Academy of Sciences. Euler was the most prolific mathematician of all time, publishing over *800 different books and papers*. His influence was felt in physics and astronomy as well. Euler's work on mathematical analysis, __Introductio in analysin infinitorum__ (1748) remained a standard textbook for well over a century. For the princess of Anhalt-Dessau he wrote *Lettres à une princesse d'Allemagne* (1768-1772), giving a clear non-technical outline of the main physical theories of the time.

One can hardly write mathematical equations without copying Euler. Notations still in use today, such as *e* and , were developed by Euler. He is perhaps best known for his research into mathematical analysis. Euler's formula:

cos(*x*) + isin(*x*) = *e* ^{(ix)}

demonstrates the relationship between analysis, trignometry and imaginary numbers, in one beautiful and elegant equation.

Leonhard Euler died in 1783, leaving behind a legacy perhaps unmatched, and certainly unsurpassed, in the annals of mathematics.

Math 895: The History of Mathematics