1. ## Angle Theta

As angle θ increases from π radians to 2pi radians, the cosine of θ
(1) increases throughout the interval
(2) decreases throughout the interval
(3) increases, then decreases
(4) decreases, then increases

2. Look at this cosine graph:

What happens when theta changes from $\displaystyle \pi$ to $\displaystyle 2\pi$?

3. ## it gets...

Originally Posted by Air
Look at this cosine graph:

What happens when theta changes from $\displaystyle \pi$ to $\displaystyle 2\pi$?
Theta increases then increases???

4. Here is a graph of $\displaystyle y = \cos{x}$ for the interval$\displaystyle [-2\pi, 2\pi]$. http://upload.wikimedia.org/wikipedi...px-Cos.svg.png

Between $\displaystyle \pi$ and $\displaystyle 2\pi$ it can be seen that $\displaystyle y = cos{x}$ is always increasing (except at the exact points of $\displaystyle \pi$ and $\displaystyle 2\pi$, which are stationary points)

5. Originally Posted by magentarita
Theta increases then increases???
Yes, that is correct. The only option which matches that is option (1).

6. ## Thanks

Thank you both for your great help.