An object moving along a straight line is slowing at a constant acceleration rate. Several data points are collected in the middle of the slowing process, for the object's velocity as a function of time.

The data points are shown on the graph below, along with a best-fit line that has been inserted to extrapolate data for the entirety of the object's motion.

In using the graph to analyze the object's motion, several different quantities about the best-fit line can be calculated.

Which quantities would be equal to the object's initial velocity, and to the object's displacement, during its slowing motion?