1.  Leonard Euler

2. Leonard Euler ( ). Born on April 15, 1707 in Basel, Switzerland, the son of a poor pastor. His father, Paul Euler, received a mathematical education from Bernoulli and transmit his knowledge to the future great mathematician, physicist and engineer.

3. In 1727 Euler was invited to St
In 1727 Euler was invited to St. Petersburg for the establishment of the local Academy of Sciences. He became professor of physics and mathematics. Euler was the first published systematic elementary manual of Mechanics in 1736.

4. Euler gives a significant contribution to the current system of mathematical symbols. For example, he introduces into use the Greek letter "pi", which expresses the ratio between the circumference and its diameter!

5. Contemporary aspect of trigonometry gives Leonard Euler in 1748
Contemporary aspect of trigonometry gives Leonard Euler in He made significant transformations in science, known today by introducing symbols sin x, cos x, tg x, corners are marked with capital letters, and opposite sides - with the small letters.

6. Write formulas for the relations between the trigonometric functions

7. Euler proved collecting formulas for trigonometric functions

8. Euler made the presentation of trigonometric curves as a function of angle, using the unit circle!

9. In 1741 Euler went to Berlin and from 1744 to 1766 he was Director of the Mathematics section of the Berlin Academy. In 1766 Euler decided to return to St. Petersburg, where he remained until the end of his life (September 18, 1783).

10. Made by Todor Ganev, Todor Mihailov, Martin Stoikov SOU Zheleznik Stara Zagora 2011

11. Special thanks to Marian,Blagovesta,Stanimira
bg.wikipedia.org/wiki/Леонард_Ойлер
графики на тригонометричните функции - Google Търсене