Update Functions.Rmd (#1722)

minor typo fix

Functions.Rmd

@@ -1106,7 +1106,7 @@ for(i in 1:10) print(i)
 `for`(i, 1:10, print(i))
 ```
 
-Suprisingly, in R, `for` can be called like a regular function! The same is true for basically every operation in R, which means that knowing the function name of a non-prefix function allows you to override its behaviour. For example, if you're ever feeling particularly evil, run the following code while a friend is away from their computer. It will introduce a fun bug: 10% of the time, it will add 1 to any numeric calculation inside the parentheses.
+Surprisingly, in R, `for` can be called like a regular function! The same is true for basically every operation in R, which means that knowing the function name of a non-prefix function allows you to override its behaviour. For example, if you're ever feeling particularly evil, run the following code while a friend is away from their computer. It will introduce a fun bug: 10% of the time, it will add 1 to any numeric calculation inside the parentheses.
 
 ```{r}
 `(` <- function(e1) {