Update api.md (reduxjs#741)

You may wish to override areStatesEqual to always return false (areStatesEqual: () => false) if you have impure reducers that mutate your store state. (This would likely impact the other equality checks is well, depending on your mapStateToProps function.)

This paragraph's last line said "is well"

Author: is0sceles

docs/api.md

@@ -122,7 +122,7 @@ When `options.pure` is true, `connect` performs several equality checks that are
 
 * You may wish to override `areStatesEqual` if your `mapStateToProps` function is computationally expensive and is also only concerned with a small slice of your state. For example: `areStatesEqual: (next, prev) => prev.entities.todos === next.entities.todos`; this would effectively ignore state changes for everything but that slice of state.
 
-* You may wish to override `areStatesEqual` to always return false (`areStatesEqual: () => false`) if you have impure reducers that mutate your store state. (This would likely impact the other equality checks is well, depending on your `mapStateToProps` function.)
+* You may wish to override `areStatesEqual` to always return false (`areStatesEqual: () => false`) if you have impure reducers that mutate your store state. (This would likely impact the other equality checks as well, depending on your `mapStateToProps` function.)
 
 * You may wish to override `areOwnPropsEqual` as a way to whitelist incoming props. You'd also have to implement `mapStateToProps`, `mapDispatchToProps` and `mergeProps` to also whitelist props. (It may be simpler to achieve this other ways, for example by using [recompose's mapProps](https://github.com/acdlite/recompose/blob/master/docs/API.md#mapprops).)