Revert "More typos"

This reverts commit 7f657dd22ac20d22698c53b23f0057e1a12c09b7.
Update cachematrix.R
Revert "Revert "More typos""

This reverts commit 10044565791f51cc444a087e267e82911b1201fd.
Revert "Revert "Revert "More typos"""

This reverts commit 31cf02988e44f3ce6e45aa652c77ddc61b718b49.