the problem is "You are told that the percentage of the viewable moon surface that is illuminated in the year 2013 is modeled by a trigonometric function. Let d represent the days since January 1, 2013. When d = 0, 100% of the viewable moon surface is illuminated. When d = 14.76 we have that 0% of the viewable moon surface is illuminated. When 0% is illuminated this is called a new moon."

"(a) Find a sine function V(d) to model this situation, where V is the percentage of the surface that is illuminated and d is the number of days since January 1,2013. Clearly show how you find the period, amplitude, horizontal shift, and midline of your function."

I know the basic y=Asin(Bx+C)+D where A is amplitude, B is period, C is horizontal shift and D is vertical shift, but i dont know what to plug in where :/