The ebook Elementary Calculus is based on material originally written by H.J. Keisler. For more information please read the copyright pages.


Some Important Sets of Real Numbers

We list some other important examples of sets of real numbers.

  1. The empty set 01_real_and_hyperreal_numbers-11.gif, which has no elements.
  2. The finite set {a1 ,..., an}, whose only elements are the numbers a1, a2,..., an.
  3. The set of all x such that x ≠ 0.
  4. The set N = {1, 2, 3, 4,...} of all positive integers.
  5. The set Z = {...,-3, -2, -1, 0, 1, 2, 3,...} of all integers.
  6. The set Q of all rational numbers. A rational number is a quotient m/n where m and n are integers and n ≠ 0.


Last Update: 2006-11-05