CPM Homework Help : CALC Problem 2-56

Zuhaib is anxiously waiting for the results of his calculus test and is pacing back and forth as shown in the graph below.

At which point ( $a, b, c,$ or $d$ ) was Zuhaib's speed the greatest? Approximate the rate.
At which point was Zuhaib's velocity the greatest? Approximate the rate.
What is the difference between speed and velocity?

Hint 1(a):

This is a distance/position graph. Notice how Zuhaib is moving forward and backwards as she paces.

Hint 2(a):

Speed is the absolute value of velocity. And velocity is the slope of a distance graph.

Hint 3(a):

At which point is the absolute value of the slope the steepest?

Hint (b):

Velocity is the slope on a distance/position graph.