The text says something about the world turning so maybe the equation has something to do with that? Maybe it is the equation for the earth's rotation. Sorry I can't find anything else, but I hope this helps a bit!
An integer divided by its opposite always equals -1: this is false. Any number which is not 0 divided by it's opposite is in fact equal to -1, but since 0 is also an integer, it's false. You are right, good job!