Euler << OY lur >>, Leonhard (1707-1783), a Swiss mathematician, contributed to nearly every branch of mathematics known during his time. There are probably more formulas, theorems, and other concepts named for Euler than for any other mathematician or scientist in history.
One of Euler’s most famous formulas elegantly relates five of the most important numbers in mathematics: e, π, i, 1, and 0. The formula is:
e πi + 1 = 0
The number e, also called Euler’s number, is the base of special numbers called natural logarithms (see Logarithms (Natural logarithms)). The value of e cannot be written exactly as a decimal, but it is approximately 2.718281. The number π is the ratio of a circle’s circumference to its diameter (see Pi). The number i, called the imaginary unit, is equal to the square root of –1.
Euler was born in Basel, Switzerland, on April 15, 1707. He did most of his work in St. Petersburg, Russia, and in Berlin. He died on Sept. 18, 1783.
