4.2 Rolle’s Theorem and the Mean Value Theorem 213
____ 14. A company introduces a new product for which the number of units sold S is
where t is the time in months since the product was introduced. During what
month does equal the average value of during the first year?
October
July
December
April
March
____ 15. A plane begins its takeoff at 2:00 P.M. on a 2200 -mile flight. After 12.5 hours, the plane
arrives at its destination. Explain why there are at least two times during the flight when the speed
of the plane is 100 miles per hour.
By the Mean Value Theorem, there is a time when the speed of the plane must equal the
average speed of 303 mi/hr. The speed was 100 mi/hr when the plane was accelerating
to 303 mi/hr and decelerating from 303 mi/hr.
By the Mean Value Theorem, there is a time when the speed of the plane must equal the
average speed of 152 mi/hr. The speed was 100 mi/hr when the plane was accelerating
to 152 mi/hr and decelerating from 152 mi/hr.
By the Mean Value Theorem, there is a time when the speed of the plane must equal the
average speed of 88 mi/hr. The speed was 100 mi/hr when the plane was accelerating to
88 mi/hr and decelerating from 88 mi/hr.
By the Mean Value Theorem, there is a time when the speed of the plane must equal the
average speed of 117 mi/hr. The speed was 100 mi/hr when the plane was accelerating
to 117 mi/hr and decelerating from 117 mi/hr.
By the Mean Value Theorem, there is a time when the speed of the plane must equal the
average speed of 176 mi/hr. The speed was 100 mi/hr when the plane was accelerating
to 176 mi/hr and decelerating from 176 mi/hr.
____ 16. Which of the following functions passes through the point and satisfies
?
a.
b.
c.
d.
e.