Rewrite as , or This is simply the regular recriprocal equation, with the axies rescaled. The standard Y axis, representing X=0, is now marked x=-1. That is, the x-numbers are moved one to the right. The old X axis of 0,1,2,3 become -1, 0, 1, 2.. The old X axis, or Y=0 becomes y=1, and we have to rescale by a factor of 3. So the old Y coordinates 0, 1, 2, 3... become 1, -2, -5, -8... And that's it.