B.O.B. - Muddiest point

Last week I missed a lot of school, because of Washington, the Senior workday, French presentations and so on. So I'm having trouble understanding this new unit and that I'm sick doesn't help in a positive way. I did understand the first worksheet and the graphing of that one, but I'm not able to connect the normal graphing function with the special sin and cosine function, to then graph it! I'm not able to really understand what the terms like amplitude and period mean, even though the explanations Jackson gave us really helped. I'm trying to catch up on work that I missed and the muddiest point of this week was just a lot of stress and not really understanding, what we were doing in class. I hope with more practice I will understand it better and have the clarity some of you talked about in their posts:)