This is programming assignment 2 of the Data Science Specialisation course module "R Programming" https://class.coursera.org/rprog-013

This function creates a "special" matrix vector x and exposes it through 4 functions that are returned as a list:

1. get() returns the input matrix x
2. set(y) assigns y, the matrix value argument to x
3. getminv() returns inv, the cached inverse of matrix x
4. setminv(minv) assigns the matrix inverse calculation minv to inv

Essentially makeCacheMatrix is a wrapper object for x - the input matrix (assumed to be invertible) y - the inverse of matrix x associated getter and setter methods

This function calculates the inverse of the matrix returned by the makeCacheMatrix$get function. It also caches the inverse result so that it can be returned directly on subsequent calls without having to recalculate it.

This function depends on an instance of the makeCacheMatrix function, passed in as mandatory argument makem.