Leonhard Euler Elif Nur Esen 200822018

Leonhard Euler Leonhard Euler was born on April 15, 1707 in Basel, Switzerland. He was the son of Paul Euler and Margaret Brucker. Paul was a Protestant minister. A year after Leonhard’s birth, Paul moved his family to Riehen, Switzerland, a suburb of Basel.

Euler’s father wanted him to follow his footsteps into the ministry to become a Protestant minister. Leonhard was sent to school in Basel where he lived with his maternal grandmother. The school was very poor and did not offer any mathematical education to the young Euler. His father, however, had taught him the basics of mathematics while living at home. Paul Euler had studied theology at the University of Basel where he attended the lectures of Jacob Bernoulli. Paul had even lived in Jacob’s house with the younger Bernoulli, Johann. Thus Leonhard’s father had some knowledge in mathematics and imparted this wisdom onto his young son. Leonhard liked the subject so much that he read mathematical textbooks and took private lessons in mathematics.

In 1720, at the age of 14, Leonhard was sent by his father to the University of Basel to prepare himself for ministry. Here his mathematical intuition was discovered by his father’s old friend, Johann Bernoulli. Euler is quoted from an unpublished autobiography saying: ... I soon found an opportunity to be introduced to a famous professor Johann Bernoulli. … True, he was very busy and so refused flatly to give me private lessons; but he gave me much more valuable advice to start reading more difficult mathematical books on my own and to study them as diligently as I could; if I came across some obstacle or difficulty, I was given permission to visit him freely every Sunday afternoon and he kindly explained to me everything I could not understand ... After three years at the University, Leonhard began his theological studies. Despite being a Christian, he did not enjoy the study of theology as much as mathematics. Johann Bernoulli assisted Leonhard in persuading his father to allow him to change his studies from theology to mathematics.

In 1726, Euler finished his mathematical studies at the University of Basel. He was already in the process of publishing a few papers and articles of mathematics. In 1727, his submission of a paper on the best arrangement for a mast on a ship got him second place for the 1727 Grand Prize of the Paris Academy. When Nicolaus Bernoulli died in St. Petersburg, the nineteen year old Euler was offered his position at the St. Petersburg Academy. At the time, Euler was hoping for a physics position at the University of Basel, but after he failed to get this job, he went to St. Petersburg. Euler was appointed to the mathematical-physical division of the Academy instead of the physiology position that Nicolaus Bernoulli’s death had left vacant. This was at the requests of Daniel Bernoulli, an applied mathematician, and Jakob Hermann, a relative and geometer. Daniel and Leonhard were both interested in applied mathematics.

In 1733, Daniel Bernoulli, who held the senior chair of mathematics at the Academy, left to return to Basel. Leonhard was appointed to the position. His better financial situation allowed him to marry Katharina Gsell. The two would have thirteen children together. At this point in his life, Euler had done work in the following mathematical areas: “number theory; differential equations and the calculus of variations; and rational mechanics.” Euler considered these three fields connected. In both 1738 and 1740, Euler won the Grand Prize of the Paris Academy. His reputation had grown at this point and he was asked by Frederick the Great to work at the Academy of Science in Berlin. Euler spent twenty-five years in Berlin, where he wrote around 380 articles. In 1766, Euler returned to St. Petersburg. At this time, Euler’s already existing eye problem became worse from a sickness and became completely blind in both eyes. Despite his new disability, Euler continued to write almost half of his entire works at this point of his life. On September 18, 1783, Euler died of a brain hemorrhage. When Euler died, the mathematician and philosopher Marquis de Condorcet commented, "...et il cessa de calculer et de vivre" (and he ceased to live and calculate).

Euler’s Contributions to Mathematics Euler’s works can be seen all over the various fields of mathematics. Many of the notations that we use everyday is due to Euler. Here is a list of some of the notation Euler initiated: f(x) for a function (1734) e for the base of natural logs (1727) i for the square root of -1 (1777) п for pi ∑ for summation (1755) Other works: Euler’s Constant: Euler’s Formula: eix = cosx + isinx Euler’s Formula (for geometry): In a simply connected polyhedron, V + F = E + 2.

Euler made a vast amount of contributions to mathematics Euler made a vast amount of contributions to mathematics. He is the most prolific mathematician of all time. His collection of works fills 75 volumes. It was Euler who dominated eighteenth century mathematics and deduced many consequences of the newly invented calculus.

Leonhard Euler April 15, 1707 – September 18, 1783

References http://scienceworld.wolfram.com/biography/Euler.html http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Euler.html http://www.worldatlas.com/webimage/countrys/europe/lgcolor/chcolor.htm