Inverse
noun
An inverted state: a state in which something has been turned (properly) upside down or inside out or backwards.
“321 is the inverse of 123.”
The result of an inversion, particularly:
A second element which negates a first; in a binary operation, the element for which the binary operation—when applied to both it and an initially given element—yields the operation's identity element, specifically:
Synonyms: additive, compositional, curve, point, multiplicative
verb
To compute the bearing and distance between two points.
adjective
Opposite in effect, nature or order.
Reverse, opposite in order.
Inverted; having a position or mode of attachment the reverse of that which is usual.