On September 18, 1783, in st. Petersburg, mino raiola HaErDe euler (. 211160 as usual began a new day. He gave one of his grandchildren said a math class, then counted the balloon flight problems. Three months ago, in Lyon south, with al gore’s fee of 0111801 061 brothers (” 151 * 0 out 3 > han a huge balloons up to 6500 feet (98000 meters). about the high altitude, then safely in 1 miles (1.61 km) away Bi plan is. Euler balloon flight mechanism. At that time, be gore’s brother is going to cost in Paris in the presence of the king Louis xvi will be a sheep to the sky. This gas ping a flying is in the second day, that is held on September 19, but the euler never listen to said it. After lunch, he and his aides calculated together found in the planet’s orbit. WangXing day he use formulas to calculate the orbit of Uranus weird, resulting in the decades after people found Neptune. However the euler no live to be found Neptune that day. That afternoon about 5 o ‘clock, he happened to spill blood brain. Then he said a” I not line “, then lose consciousness. On the night he died on the history of mathematics, and human’s most productive a life so “beam.

Mathematicians was born in Switzerland, euler his life in Berlin and the main time spent at st. Peter. He to mathematics, physics and engineering to every field of had a tremendous impact. He is great, not only lies in the importance of his discovery, no one can and, and its quality also is breathtaking. The works of euler part included in the “complete collection of euler (4)… Yang 0 ship, has now (4 compiled more than 73 volumes, the thickness of each volume is 600 pages. Life the last 17 years euler, that in 1766 he returned to fort to PA3587U-1BRS battery Peter to him at the age of 76, died at the age of, calm. Despite his personal life is full of tragedy, but his life works from this period. Half That includes a 775-page explore the moon operation of the papers, a quite an influential generation of math books, a three volumes this collection points. These # is and his weekly for st Petersburg scientific journals to write a mathematics paper writing out at the same time. The most exciting surprised the different is in that time, he basically don’t study, also don’t write. 1766 years back to st. Petersburg soon, euler lost sight of. In 1771 he made cataract surgery, but the operation failed, led to his completely blind. His thousands of pages of theory works is by memory of oral out.

30 years ago, when the euler eyesight is normal, he wrote a brief paper, discussion from elder brother in Johannesburg (you Mingcambio) an interesting question. Elder brother in Johannesburg euler in st. Petersburg home from far, is located within the territory of the Prussian an open city full of flowers. In the early eighteenth century, people also completely unexpected 1 city will be affected by the second world war ii the ravages of war. When one of the prints and this is located in the skin of river axel city thriving scene, river is full of goods, shore double fleet by local merchant family lived a rich in the rich life. And the healthy development of the financial strength to the city on the river, the city government uncommon built more than 7 bridge. Most of the bridge to endure Buddha “Yi) at Cardiff this beautiful ? island. The island is skin geer river two branches of caught in the middle of sand bars, a city located in the island. In addition to the two bridge will be skin geer river two branches of even

Figure 2.1 at the bridge in Johannesburg. 1875 years ago in Johannesburg in the layout of the elder brother, of which the nanotubes is Buddha said Cardiff 0 is the land, the island, skin geer two branches of the river they caught in the middle. Elder brother in Johannesburg problem requires people to find through the city seven bridge and each bridge only go again path. In 1736, mino raiola Hal DE euler discusses the problem invented the graph theory. He will be four land areas as “dot” (eight to!) ), each bridge as a side 4 to 8 >, this got includes four points, seven side of the chart. Then he proved the elder brother in Johannesburg figure, it does not exist when bridge once walked only through the city and the route. Together (figure 2.1 . Living in Johannesburg elder brother who once living comfortably rich, especially like to play intelligence game, one of the “seven bridge problem” is like this: “the people could not repeat through seven bridge?” at that time who also have no way to do this. Then, in 1875, built HP dv2000 battery a new Bridges, people found that can ask according to the will go through.

Xinqiao construction in the 150 years ago, which was in 1736, euler put forward a powerful mathematical reasoning, in accordance with specified at 7 bridge layout, doesn’t exist puzzle required in the path. He that article brief paper not only solve the elder brother nice? Problems, but also in accidentally opened a new math: graph theory. Double township, graph theory has become the foundation of network problems thinking. After the death of the euler several will, graph theory has gradually mature, most development during this mathematicians have made a contribution. In order to open the gate, we network field first come to review prompted euler thinking first graph theory thinking of the process.

The simple and exquisite euler proof, even without learn training, also very easy to understand. But, to write the history of this question is not his proof of fruit, but he and solve problems among the process. The most amazing to party euler, to get the elder brother in Johannesburg bridge issue is seen as a starting point by point and links the edge of a graph of. For this problem, he points to represent each separated by rivers land areas respectively, employing, 8,and he said. The next 0 will pick up the bridge as the land even edge. So he would get from point and edge of graphics.

Euler through a simple found proof that the elder brother in Johannesburg does not exist through each bridge a route through the city. The discovery is: figure with the edge of the has an odd number of points, not the starting point of the trip, what, is the destination. And through all the continuous route bridge can have a starting point 0 and a destination. That way, if a figure with two of the edge of the has an odd number of points, not that there exists a route. In the elder brother in Johannesburg figure this point has four, so can’t find the necessary route. And the purpose of the euler mentioned in argument, it is to show whether there are not take & route in our argument is clever, but in the method of attributes. Figure itself The bridge with elder brother, for example, no matter how Dell Inspiron 1100 battery much we clever, and also cannot find the necessary road stomach in Johannesburg city finally believed the euler argument, not in vain to search for the most convenient route. In 1875, they in 8 and (: built a new bridge between the two points, the edge between increased to 4. This will only have two belt has an odd number of edge points (and 0 >. This way, looking for the most simple route is very straight to pick up the search for this line. Maybe the secret, it is also the basic principle of building a bridge?