What is a positive two fixed three

One positive, two definite, three-phase, etc. refer to the special requirements specified and emphasized in proving or solving problems with inequality a + B ≥ 2 √ ab
2.1
A. B must be positive
2
1. When a + B is constant, we can know the maximum value of a · B;
2. When a · B is constant, we can know the minimum value of a + B
4 three equal:
If and only if a and B are equal, the equation holds
① A=B ↔ A+B=2√AB；
② A≠B ↔ A+B>2√AB．

Several definitions in Mathematics

Complex number refers to the number a + bi which can be written in the following form, where a and B are real numbers and I is imaginary number unit (i.e. - 1 open root). It was first introduced by Cardan, a scholar in Milan, Italy, in the 16th century. After the work of d'Alembert, demover, Euler and Gauss, this concept has been gradually accepted by mathematicians, It is the most basic object and tool in complex function theory, analytic number theory, Fourier analysis, fractal, fluid mechanics, relativity, quantum mechanics and other disciplines
Trigonometric function is a kind of transcendental function in elementary function in mathematics. Its essence is the mapping between the set of any angle and the variable of a ratio set. Generally, trigonometric function is defined in the plane rectangular coordinate system, and its domain is the whole real number domain. Another definition is in the right triangle, It includes six basic functions: sine, cosine, tangent, Cotangent, secant and cosecant. Because of the periodicity of trigonometric function, it does not have the inverse function in the sense of single valued function. Trigonometric function has more important applications in complex numbers, Trigonometric function is also a common tool. Generally, for the mathematical object x, we can define the complex column {lambda}_ X(n)\}_ {n = 1} ^ {infty}, such as l (s, x) = \ sum_ {n=1}^{\infty}\frac{\lambda_ The Dirichlet series with X (n)} {n ^ s}, res > 1 and Euler product is called L-function of X. 1. Generally speaking, the source of L-function consists of two types: arithmetic L-function and Automorphic L-function. These two are closely related. According to p.r.langlands' conjecture, generally speaking, all meaningful L-functions come from automorphic L-function, Automorphic L-functions: L-functions in the form of holomorphic modules, Maass L-functions, standard L-functions, etc

20 exercises of mathematical figure calculation
Come on, how many, how many ~

In order to promote the construction of new socialist countryside and make Hunhe River become the inland river of Shenyang, Shenyang has invested a lot of money to control Hunhe River pollution. A comprehensive sewage treatment plant has been set up in the suburb of Shenyang. There is a ton of sewage to be treated in the reservoir, and the sewage flowing into the reservoir from the urban area is increased by a fixed flow of B tons per hour

What is a positive two fixed three