Inverses include: multiplicative inverse of a number (reciprocal), inverse function, matrix inverse, etc. A subject tag such as (linear-algebra), (algebra-precalculus) or (arithmetic) should be added to clarify in which sense "inverse" is used. This tag should never be the only tag on a question.

An inverse is an operation that reverses the effect of another operation. This is a broad concept that arises in many areas of mathematics.

- Multiplicative inverse: $2^{-1} = 1/2$
- Inverse function: $\sin^{-1}x$ is the inverse of sine
- Inverse matrix $A^{-1}$
- Left and right inverses of group elements, of operators between linear spaces, etc.