Answer:
Linked an image
Explanation:
Okay, basically since it is y=2co3x you know that the amplitude is 2, so rather than going to +1 and -1, you now go to +2 and -2. Since it's cosine, you also know that you start at the maximum rather than the intercept, so the starting point is at (0,2).
I'm assuming that you need to graph 2 periods, and to find the periods you divide 2pi/b, so, in this case, 2pi/3
Then lastly you need to find the four points between 0 and 2pi/3, so you divide 2pi/3/4 to get 2pi/12=pi/6
If you have any other questions just comment and I'll respond when I see it.