1, the definition of rational number
Rational number is a mathematical term, including integer and fraction. Integers and fractions are collectively called rational numbers. Integers include positive integers, 0 and negative integers, such as 1,-1, 0. Other fractions include positive and negative fractions, such as 1/2, -2/3 and so on.
2, the nature of rational numbers
Rational numbers can be expressed as integers and fractions. Rational numbers have four operations: addition, subtraction, multiplication and division, and the operations satisfy the laws of exchange, association and distribution. Rational numbers are closed, that is, the sum-difference product quotient of any two rational numbers is still rational. Rational numbers are symmetric, that is, for any two rational numbers A and B, a+b=b+a and ab=ba are discrete.
3. There are mathematical concepts such as irrational numbers and complex numbers.
Irrational numbers refer to infinite cyclic decimals, π, e, etc. These numbers can't be expressed by fractions, but complex numbers, which are very important in mathematics and practical applications, refer to mathematical objects with real parts and imaginary parts, such as 2+3i. The introduction of complex numbers can solve many practical problems, such as fractional mechanics, signal processing and so on.
4, the introduction of irrational numbers
Besides integers and fractions, irrational numbers are also introduced into mathematics. Irrational numbers refer to infinite cyclic decimals, π, e, etc. These numbers can't be expressed by fractions, but they are very important in mathematics and practical application. In geometry, π is a very important constant, which represents the ratio of the circumference to the diameter of a circle; In economics, e is the base of a natural logarithm, which is also very meaningful.
Rational numbers have two important applications.
The position of 1 in mathematics
Rational number is one of the most basic number systems in mathematics, including integers and fractions. The concept of rational number is the basis of mathematics, and the operation of rational number is also a very important operation in mathematics. Through the operation of rational numbers, we can get many useful conclusions and formulas, such as Pythagorean theorem and square difference formula.
2. Application in real life
Rational numbers not only play an important role in mathematics, but also are widely used in real life. In the financial field, the calculation of interest requires the operation of rational numbers; In the field of physics, the calculation of physical quantities such as speed and acceleration also requires the operation of rational numbers.