The circular frequency v of oscillation of a point is given by v = 2/period, What happens

Question:

The circular frequency v of oscillation of a point is given by v = 2π/period, What happens when you add two motions that have the same frequency or period? To investigate, we can graph the functions y(t) = 2 sin(π i/5) and y(t) = sin(π i/5) + cos(π t/5) and look for similarities. Armed with this information, we can investigate by graphing the following functions over the interval [-5, 5]:
(a) y(t) = 3 sine (π t/5) - 5 cos(π t/5) + 2 sin((π t/5) - 3)
(b) y(t) = 3 cos(πt/5 - 2) + cos(π t/5) + cos((πt/5) - 3)