So let's say, let's say that's our relative maximum. Well, as we approach our relative maximum for values for, as we have x-values that are approaching the x-value of our relative maximum point, as we approach it from values below that x-value, we see that we have a positive slope. Our function needs to be increasing. So over here, over here, we see f is increasing, going into the relative maximum point. f is increasing, which means that the derivative of f, the derivative of f must be greater than zero. And then after we pass that maximum point, after we pass that maximum point, we see that our function needs to be decreasing. Let me just add another color.