Edited by Valentin Fadeev, Sunday, 18 Sep 2011, 23:23
This is quite a minor trick and like many things listed here may seem quite trivial. However, this is one of those few occasions when I had the tool in mind, before I actually got the example touse it on. Consider:
which does not really require a great effort to solve. But forget all the standard ways for a moment and add to both parts:
Hope this can be stretched to use in more complicated cases
Going beyond dx
This is quite a minor trick and like many things listed here may seem quite trivial. However, this is one of those few occasions when I had the tool in mind, before I actually got the example touse it on. Consider:
which does not really require a great effort to solve. But forget all the standard ways for a moment and add to both parts:
Hope this can be stretched to use in more complicated cases