What is the concept of real number? Real number is an important concept in mathematics, which includes all rational numbers and irrational numbers.
The definition of real numbers can start with rational numbers. Rational number is a number that can be expressed as the ratio of two integers, including integers, fractions and decimals. For example, 2, -3, 1/2 and 0.25 are all rational numbers.
But some numbers cannot be expressed as the ratio of two integers. These numbers are called irrational numbers. Irrational numbers cannot be written in the form of fractions, and their decimal parts will not be repeated. For example, π (π) and √ 2 (the square root of 2) are irrational numbers.
The definition of real numbers can be understood by the number axis. The number axis is a straight line, and each point on it corresponds to a real number. Integer points on the number axis correspond to rational numbers, and other points on the number axis correspond to irrational numbers. Real numbers include all points on the number axis, whether rational or irrational.
Real numbers have many important properties. Some of these properties include the proximity of addition and multiplication, that is, the sum or product of two real numbers is still a real number; Comparability of real numbers, that is, real numbers can be compared through the size relationship; And the density of real numbers, that is, between any two real numbers, has infinite other real numbers.
The concept of real numbers is widely used in mathematics. It is the basis of analytic geometry, calculus, real analysis and other fields. The concept of real numbers also plays an important role in practical applications such as physics, engineering and economics.
Methods of learning mathematics
1. Understand the basic concepts: First, understand the basic concepts of mathematics, such as numbers, operation symbols, algebra, geometry, etc. Establishing the understanding and cognition of these concepts is the basis of learning mathematics.
2. Mastering basic skills: There are many basic skills and methods in mathematics, such as addition, subtraction, multiplication and division, fractions, percentages, square roots and so on. Mastering these basic skills is very important for solving mathematical problems.
3. Do more exercises: Mathematics is a subject that needs to be practiced, and doing more exercises can improve mathematics ability. You can start with simple topics, gradually increase the difficulty and constantly challenge yourself.