•A sinusoidal function is a function in sine or in cosine •The amplitude of a graph is the distance on the y axis between the normal line and the maximum/minimum. It is given by parameter #a# in function #y = asinb(x - c) + d or y = acosb(x - c) + d# •The period of a graph is the distance on the x axis before the function repeats itself. Hope this helps you! :)