A function is represented by y = cos (2π/5)x - 1. Determine the amplitude and period of the function. What is the equation of the midline?A) amplitude is 1; period is 5; y = 0 B) amplitude is 1; period is 2/5; y = 1 C) amplitude is 1; period is 5; y = −1 D) amplitude is 1; period is 2π; y = −1 (Please explain how you get it)

Given that: y = cos(2pi/5)x -1The general form of cos function is y = A cos(Bx+C) +DSo amplitude = A=1Period = 2pi/B=2pi/(2pi/5)= 5Phase shift = -C/B= 0Vertical shift = D=-1So the equation of the midline is y=-1Sot he correct option is C.