Zero (0) is a
number.
It was introduced into
mathematics relatively late, during the early
800s in
Indian books.
Prior mathematical systems, such as the
Babylonian or
Greek, did not use zero at all, but still succeded quite well for everyday purposes.
The following are some basic rules for dealing with zero.
These rules apply for any complex number x, unless otherwise stated.
- Addition: x + 0 = x and 0 + x = x. (That is, 0 is an identity element with respect to addition.)
- Subtraction: x - 0 = x and 0 - x = -x.
- Multiplication: x × 0 = 0 and 0 × x = 0.
- Division: 0 / x = 0, for nonzero x. But x / 0 is undefined, because 0 has no multiplicative inverse.
- Exponentiation: x0 = 1, except that the case x = 0 may be left undefined in some contexts. For all positive x, 0x = 0.
The year zero does not exist.
Instead there is a "zero point" in time between the years [1 B.C.]
? and
1.