Vedas were born in Boitu (1540) and Fontaine. -le-Comte (modern province). 1603 12 13 died in Paris. I studied law and worked as a lawyer when I was young. Later, he engaged in political activities and served as a member of parliament.
In the war against Spain, he cracked the enemy's code for the government. David is also devoted to mathematical research. He was the first to consciously and systematically use letters to represent known numbers, unknowns and their powers, which brought great progress to the theoretical research of algebra. David discussed various rational transformations of the roots of the equation, and found the relationship between the roots of the equation and the coefficients (so people call the conclusion describing the relationship between the roots and the coefficients of a quadratic equation in one variable "Vieta Theorem").
David engaged in mathematical research only out of love, but he accomplished masterpieces in algebra and trigonometry. His Mathematical Laws Applied to Triangles (1579) is one of David's earliest mathematical monographs, and it may be the first book in Western Europe that systematically discusses six methods for trigonometric functions to solve planar and spherical triangles. He is called the father of modern algebraic symbols.
David also specially wrote a paper "Tangent Angle", which preliminarily discussed the general formulas of sine, cosine and tangent chord, and applied algebraic transformation to trigonometry for the first time. He considered the equation with multiple angles, gave the function of expressing COS(nx) as COS(x), and gave the expression of multiple angles when n≤ 1 1 equals any positive integer.
Extended data:
As early as 3600 years ago, the ancient Egyptians wrote down mathematical problems on papyrus, which involved equations with unknowns.
Around 825 AD, Al Hualazimi, a mathematician in Central Asia, wrote a book called "Elimination and Return", focusing on solving equations.
China's equation comes from the ancient mathematical monograph Nine Chapters Arithmetic, the eighth volume of which is called Equation. "Fang" means juxtaposition, and "Cheng" is a vertical form with calculation.
Volume 8 (1) is: Today, there are three catches on the upper grain, two catches on the middle grain and one catch on the lower grain, which is actually thirty-nine fights; Two catches on the grain, three catches on the grain, and one catch on the grain, with 34 fights; Catch the first grain, catch the second grain, catch the third grain, and actually fight 26 battles. What are the geometric shapes of the upper, middle and lower crops?
(At present, there are 3 bundles of first-grade millet, 2 bundles of middle-grade millet, low-grade millet 1 bundle and 39 bundles of millet * * * *; 2 bundles of first-class millet, 3 bundles of middle-class millet, lower-class millet 1 bundle, producing 34 buckets of millet; There are 1 packages of excellent millet, 2 packages of medium millet, 3 packages of poor millet and 26 packages of millet. How many barrels of millet can be produced by first-class millet 1 bundle, medium millet 1 bundle and low millet 1 bundle? )
Vernacular translation: Volume 8 (1) reads: At present, there are three points for grain, two points for COFCO and one point for grain, which is actually thirty-nine buckets; Two points on the grain, three points on the grain, one point on the grain, actually thirty-four fights; Up to one point, middle to two points, down to three points, actually two sixteen fights. What are the upper, middle and lower lines?
(Now there are three bundles of first-class millet, two bundles of medium-class millet, one bundle of lower-class millet, and thirty-nine buckets of rice * * *; Two bundles of first-class millet, three bundles of medium-class millet and inferior millet, and thirty-four buckets of rice. There is a bundle of first-class millet, a bundle of second-class millet, a bundle of third-class millet, and 26 meters. 1 How many barrels of yellow rice can I start with each bundle of fine millet, a bundle of medium millet and 1 bundle of inferior millet? )
A: The grain on the top is one, nine and one quarter, the grain in the middle is one, four and one quarter, and the grain on the bottom is one, two and three quarters.
Vernacular translation: He replied: a little on the grain, nine measures, one quarter, a little on the grain, four measures, one quarter, a little on the grain, two measures, three quarters.
Equation technique says: use three hands for the upper grain, two hands for the middle grain, and one hand for the lower grain, actually thirty-nine hands, and put it on the right. Middle, left, right. Multiply the grain in the right row by the middle row and divide it directly. Multiply by seconds and then divide by a straight line. However, in the case of the Bank of China, those crops that can't be planted are divided into left and right. If there are endless crops on the left, there are laws above and reality below. Reality is the next reality.
Neutralization, multiplication, and division of the next grain. I am as good as Zhonghe. This is the reality of Zhonghe. The upper grain is also based on the right line multiplied by the right line, but the lower grain and the middle grain are excluded. I am one of the top stubble, which is the reality of the top stubble. Everything is like the law, and each has its own struggle.
Vernacular translation: the equation method is: the upper grain has three points, the middle grain has two points, and the lower grain has one point. In fact, there are thirty-nine barrels on the right. Middle, left, right. Take the right line, go up, take the grain, and take the middle line directly. Multiplied by seconds, you can also cancel it directly. In the Bank of China, Zhonghe takes the left line and the straight line. On the lower left is an endless crop, with laws on it. The following is true. The fact that the grain is sown immediately.
Seek neutrality, and remove grain because of law multiplication. I am like neutralization, which is the fact of neutralization. Seeking the upper grain is also because the method takes the right side down and removes the lower grain and the middle grain. I like the fact that I am on the grain, and I am on the grain. In fact, they are all like dharma, and each has its own fight.
The above is a ternary linear equation group from "Nine Chapters Arithmetic", which shows how to solve this equation group by eliminating elements by "multiplication, direct division".
Liu Hui, a great mathematician in Wei and Jin Dynasties, made a lot of comments on Nine Chapters of Arithmetic around 263 AD, and introduced the equations: two things go further, three things go three ways, all of which are like numbers. Parallel to a line is called an equation. He also created a simpler "mutual multiplication and mutual elimination" solution equation.
Baidu Encyclopedia-Equation