diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..6c86c4db4b0 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,27 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
 makeCacheMatrix <- function(x = matrix()) {
+    inv <- NULL
+   set <- function(y) {
+     x <<- y
+     inv <<- NULL
+   }
+   get <- function() x
+   setinv <- function(inverse) inv <<- inverse
+   getinv <- function() inv
+   list(set = set, get = get, setinv = setinv, getinv = getinv)
+   }
 
-}
-
-
-## Write a short comment describing this function
+## cacheSolve is a function which computes the inverse of the special "matrix" 
+## returned by makeCacheMatrix above. If the inverse has already been calculated 
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
-}
+## Return a matrix that is the inverse of 'x'
+   inv <- x$getinv()
+   if(!is.null(inv)) {
+     message("getting cached result")
+     return(inv)
+   }
+   data <- x$get()
+   inv <- solve(data, ...)
+   x$setinv(inv)
+   inv
+  }