Decreasing x: The opposite of increasing x, when the x-coordinate component is getting smaller as time progresses.
Slope: Slope refers to how steep a line or curve is. When discussing increasing x, we can think of slope as positive (uphill) since it indicates movement to the right.
Instantaneous rate of change: It measures how quickly something changes at an exact moment in time. In this context, it would represent how fast an object's position changes with respect to its x-coordinate at any given instant.