inverse
mathematical operation or function which undoes the effect of another entity of the same type
multiplicative inverse
of a number x, 1 divided by x
opposite number
number that, when added to the original number, yields zero
Inverse function
function that "reverses" another function: if the function f applied to an input x gives a result of y, then applying its inverse function g to y gives the result x, and vice versa. i.e., f(x) = y if and only if g(y) = x
reciprocal function
function mapping a number to its reciprocal