Leonhard Euler (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 a une princesse d'Allemagne (1768-1772), 
giving a clear non-technical outline of the main physical theories of the 
time.

One can hardly do math without copying Euler. Notations still in use today, 
such as e and pi, were introduced in Euler's writings. He is perhaps best known 
for his research into mathematical analysis. Euler's formula

    cos(x) + isin(x) = e (ix)

demonstrates the relationship between algebra, complex analysis, and trigonometry.
From this equation, it's easy to derive the equation

    e(pi i) + 1 = 0

which relates the fundamental constants: 0, 1, pi, e, and i in a single
beautiful and elegant statement.

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