opposite in nature or effect or relation to another quantity

something inverted in sequence or character or effect

a function obtained by expressing the dependent variable of one function as the independent variable of another; f and g are inverse functions if f(x)=y and g(y)=x

(mathematics) one of a pair of numbers whose sum is zero; the additive inverse of -5 is +5

(mathematics) one of a pair of numbers whose product is 1: the reciprocal of 2/3 is 3/2; the multiplicative inverse of 7 is 1/7