Suppose you toss a ball upward into the air and then catch it. Must the ball's velocity have been zero at some point? {{CMD_7}} Suppose you drive a car on a straight stretch of highway from toll booth to another toll booth {{MATH_8}} miles away in half of an hour. Must you have been driving at {{MATH_9}} miles per hour at some point? {{CMD_10}} Suppose two different functions have the same derivative. What can you say about the relationship between the two functions? {{CMD_11}}