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. The slope of the tangent line right at that bottom point would have a slope of zero. So I feel really good about that response. Let's do one more of these.