First, of course, |-x-1|= |x+ 1|. Since that is never negative, is never less than 1, is never larger than -1 and so is never larger than 1. Of course when x= -1, |-x-1|= 0, and y= 1. Since |x+1| can be arbitrarily large and is an increasing function, y can be any negative number. That gives the range as