Z represents a set of integers in a set, that is, a set composed of all integers, including zero, all positive integers and all negative integers. Positive integers are 3, 7, 53, 679, 3457, 65443, 8 ...; Negative integers include -4, -6, -7, -346, -98. Z comes from the German "Zahlen". 192 1 year, the German mathematician Nott introduced the concept of integer ring in the ideal theory of whole ring, so the integer set was represented by the capital letter Z.
Common number sets and number set symbols in mathematics
1, positive integer set. The positive integer set is the set of all positive integers, and the symbol set of the positive integer set is the capitalized English letter "N+" or "6N water". Positive integers include all positive integers: 1, 2, 3, 4, 5, ......
2. natural number set natural number set is the set of all natural numbers, and the set of symbols is the capitalized English letter "n". Natural numbers include positive integers and 0.
3. The integer set is the set of all integers, and the symbol set is a capitalized English letter "z". Integers include negative integers, 0 and positive integers.
4. Rational number set. The set of rational numbers is the set of all rational numbers, and the set of symbols is the capital English letter "Q". Rational numbers include integers, finite decimals, infinite cyclic decimals and fractions that can be converted into finite decimals and infinite cyclic decimals.
5. Set of real numbers. Real numbers can be divided into rational numbers and irrational numbers. Irrational numbers include infinite numbers and infinite acyclic decimals. Common irrational numbers in middle school mathematics, such as pi and the base e of natural logarithm. The symbol set of the real number set is the capital English letter "R".
6. Complex set. The symbol set of a complex number set is usually represented by the capitalized English letter "C". Real complex numbers include real numbers and imaginary numbers. Including rational numbers and irrational numbers. Imaginary numbER refers to the number of imaginary part b in "atbi(aER, ber)".