And they told us to estimate it, but all of these are way off. Having a negative two derivative would mean that as we increase our x, our y is decreasing. So if our curve looks something like this, we would have a slope of negative two. If having slopes in this, a positive of.1, that would be very flat. Down here we might have a slope closer to.1. Negative.1, that might be closer on this side, where it's downward sloping, but very close to flat. A slope of zero, that would be right over here at the bottom where right at that moment, as we change x, y is not increasing or decreasing.