add comments

Author: ahaedike

cachematrix.R

@@ -1,7 +1,8 @@
-## Put comments here that give an overall description of what your
-## functions do
+## Matrix inversion is usually a costly computation and there may be some benefit to 
+## caching the inverse of a matrix rather than compute it repeatedly 
+## These functions cache the inverse of a matrix.
 
-## Write a short comment describing this function
+## This function creates a special "matrix" object that can cache its inverse.
 
 makeCacheMatrix <- function(x = matrix()) {
   i <- NULL
@@ -18,7 +19,9 @@ makeCacheMatrix <- function(x = matrix()) {
 }
 
 
-## Write a short comment describing this function
+## This function computes the inverse of the special "matrix" returned by makeCacheMatrix above. 
+## If the inverse has already been calculated (and the matrix has not changed), 
+## then the cacheSolve should retrieve the inverse from the cache.
 
 cacheSolve <- function(x, ...) {
     ## Return a matrix that is the inverse of 'x'