An inverse function links the output value back to the input value, meaning it is the original function in reverse. An inverse function is written as 𝑓\(^-\)\(^1\)(𝑥).

A function links an input value to an output value. Functions are written in function notation with the name of the function (usually f or g), a variable written in brackets and an expression .

For example, the inverse of 4 is 0.25 because 4 * 0.25 = 1. There are several algorithms to compute a matrix inverse, and each algorithm has several variations. Three common algorithms are LUP ("lower ...