The graph of this sinasoid wave is B) f(x) = 3cos(x) + 3
We can tell this for two reasons. Firstly, the multiplier in the beginning is always equal to half of the height of the graph. Since the graph goes as high at 6 and as low as 0, we know the overall height is 6. Half of that is 3. This means that we have a 3 for the multiplier.
Next, we can decide between sin and cos by determining that it starts up and ends down. Sin starts moving up at the beginning and cos moves up at the beginning. Therefore, it must be the cos.