Answer:
y = cos (2x + 2π) - 5/2
Step-by-step explanation:
y = a cos (bx + c) +d
a = Amplitude =1
period = 2π/b =π
b= 2
phase shift c/b = π
c/2 =π
c =2π
vertical translation = 5/2 units
d = -5/2 downwards
therefore substituting the values
y=1 cos (2x +2π) - 5/2
y = cos (2x + 2π) - 5/2 ;equation for the function