Question

The average value of the function f(x)= cos ( 1/2 x) on the interval [ -4,0] is ...

A.- 1/2 sin(2)
B.-1/4 sin (2)
c. 1/2 cos (2)
d. 1/4 sin (2)
e. 1/2 sin (2)
I substituted -4 and 0, but that does not match any of the multiple choice answers that are given.

Help please!

Answer 1

did you get

1/2sin(-2)?

Answer 2

if so then you can pull the - out of the sin function. so you end up with -1/2sin(2)

Answer 3

http://www.wolframalpha.com/input/?i=sin%28-2%29%2F2

Answer 4

How did you do it? Can you show me the steps/
I saw the link, but I would like to se the work, Tha was not what I got, I must have made a mistake somewhere along the line.