Answer: 5
Work Shown:
y = -3cos(2pi/5x) is in the form y = A*cos(Bx) where |A| is the amplitude and B helps determine the period T. In this case, B = 2pi/5
T = 2pi/B
T = 2pi/(2pi/5) ... replace B with 2pi/5
T = (2pi/1) divided by (2pi/5)
T = (2pi/1) * (5/2pi)
T = 5 ... note how the '2pi' terms canceled out
So the period is 5
This means that every 5 units on the x axis is when the graph repeats itself.
