| 31. | The most influential mathematician of the 18th century was arguably Leonhard Euler.
|
| 32. | Its Euler characteristic is therefore 1-2 + 1 = 0.
|
| 33. | Euler succeeded him as the head of the mathematics department.
|
| 34. | He was a contemporary and close friend of Leonhard Euler.
|
| 35. | Euler diagrams contain only the actually possible zones in a given context.
|
| 36. | So Euler's theorem yields, and we get 7 222.
|
| 37. | Where \ gamma is equal to Euler's constant.
|
| 38. | Its Euler characteristic is 0, by the product property.
|
| 39. | The proof is an adaptation of the product expansion idea of Euler.
|
| 40. | Lagrange solved this problem in 1755 and sent the solution to Euler.
|
