Online Encyclopedia Search Tool

Your Online Encyclopedia


Online Encylopedia and Dictionary Research Site

Online Encyclopedia Free Search Online Encyclopedia Search    Online Encyclopedia Browse    welcome to our free dictionary for your research of every kind

Online Encyclopedia

Additive inverse

The additive inverse, or opposite, of a number n is the number which, when added to n, yields zero. The additive inverse of n is denoted −n.

For example:

  • The additive inverse of 7 is −7, because 7 + (−7) = 0;
  • The additive inverse of −0.3 is 0.3, because −0.3 + 0.3 = 0.

Thus by the last example, −(−0.3) = 0.3.

The additive inverse of a number is its inverse element under the binary operation of addition. It can be calculated using multiplication by −1; that is, −n = −1 n.

Types of numbers with additive inverses include:

Types of numbers without additive inverses (of the same type) include:

But note that we can construct the integers out of the natural numbers by formally including additive inverses. Thus we can say that natural numbers do have additive inverses, but because these additive inverses are not themselves natural numbers, the set of natural numbers is not closed under taking additive inverses.

See also

Last updated: 10-24-2004 05:10:45