13. What is the average value of the function f(x) = x sin(x2) over the interval [2,4]?

 

A. sin 4 + 2 sin 16

B. –sin 4 + 2 sin 16

C. (cos 4 – cos 16)/2

D. (cos 4 – cos 16)/4

E. (-cos 4 + cos 16)/4

 

 

 Solution: The answer is D

 

The average value of the function f(x) = x sin(x2) over the interval [2,4] is given by integrating f(x) over the same interval and dividing by the length of the interval. That is, 

 Consequently,