diff --git a/.RData b/.RData
new file mode 100644
index 00000000000..035319804d8
Binary files /dev/null and b/.RData differ
diff --git a/.Rhistory b/.Rhistory
new file mode 100644
index 00000000000..86a2c5afbaa
--- /dev/null
+++ b/.Rhistory
@@ -0,0 +1,27 @@
+source("cachematrix.R")
+q()
+source("cachematrix.R")
+a <- makeCacheMatrix(matrix(1:4,2))
+a$get()
+a$getInverse()
+a$set(matrix(5:8,2))
+a$get()
+cacheSolve(a)
+cacheSolve(a)
+a$getInverse()
+b = a$getInverse()
+a$get() %*% b 
+q()
+q()
+source("cachematrix.R")
+a <- makeCacheMatrix(matrix(1:4,2))
+a$get()
+a$getInverse()
+a$set(matrix(5:8,2))
+a$get()
+cacheSolve(a)
+cacheSolve(a)
+a$getInverse()
+b = a$getInverse()
+a$get() %*% b
+q()
diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..53bb07f753d 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,39 @@
 ## Put comments here that give an overall description of what your
 ## functions do
 
-## Write a short comment describing this function
-
+## This function creates a special "matrix", which is really a list containing 
+## a function to
+## 1. set the value of the matrix
+## 2. get the value of the matrix
+## 3. set the value of the inverse of the matrix
+## 4. get the value of the inverse of the matrix
 makeCacheMatrix <- function(x = matrix()) {
-
+	i <- NULL
+	set <- function(y) {
+		x <<- y
+		i <<- NULL
+	}
+	get <- function() x
+	setInverse <- function(solve) i <<- solve
+	getInverse <- function() i
+	list(set = set, get = get, 
+		setInverse = setInverse, 
+		getInverse = getInverse)
 }
 
 
-## Write a short comment describing this function
-
+## This function calculate the inverse of the special "matrix" created with 
+## makeCacheMatrix function. However, it first check to see if the inverse
+## of the matrix has already been calculated.
 cacheSolve <- function(x, ...) {
         ## Return a matrix that is the inverse of 'x'
+	i <- x$getInverse()
+	if(!is.null(i)) {
+		message("getting cached data")
+		return(i)
+	}
+	data <- x$get()
+	i <- solve(data, ...)
+	x$setInverse(i)
+	i
 }