The additive inverse of a number a is the number that, when added to a, yields zero.
For example, 5 + (-5) = 0
This number is also known as the opposite (number), sign change, and negation.
For a real number, it reverses its sign: the opposite to a positive number is negative, and the opposite to a negative number is positive.
Additive inverse is closely related to subtraction, which can be viewed as an addition of the opposite:
- a − b = a + (−b).
Conversely, additive inverse can be thought of as subtraction from zero:
- −a = 0 − a.
Hence, (-a) is the additive inverse of a , such that a + (-a) = 0.