1. The problem statement, all variables and given/known data I have a cubic function, y=(x-6)(x-1)(x-9) or y=x3-16x2+69x-54 I then have two tangents, y=7.75x+14.75 and y=-6.25x+56.25 What I need to find is another two tangents that are parallel. 2. Relevant equations 3. The attempt at a solution What I know needs to be found is the two x points which the tangents cross, the rest from there on is simple enough. So how do I find the two x points parallel to the other tangents. Any Help is much appriectated.