inverse

中文： 否命题、逆元

1. An inverted state: a state in which something has been turned (properly) upside down or (loosely) inside out or backwards. · Cowgirl is the inverse of missionary.· 321 is the inverse of 123.
2. The reverse of any procedure or process. · Uninstalling is the inverse of installation.
3. A ratio etc. in which the antecedents and consequents are switched. · The inverse of a:b is b:a.
4. The result of a circle inversion; the set of all such points; the curve described by such a set. · The inverse P‘ of a point P is the point on a ray from the center O through P such that OP × OP‘ = r² or the set of all such points.
5. The non-truth-preserving proposition constructed by negating both the premise and conclusion of an initially given proposition.
6. The negative of a given number. · The additive inverse of x is -x, as x-x=0, as 0 is the additive identity element.
7. One divided by a given number. · The multiplicative inverse of x is x⁻¹, as x×x⁻¹=1, as 1 the multiplicative identity element.
8. A second function which, when combined with the initially given function, yields as its output any term inputted into the first function.

复数 inverses