Answer:
<u>Step-by-step explanation:</u>
y = A cos (Bx - C) + D
- A (amplitude) = max - D
- B = Period/2π ---> Period is the distance from max to next max
- C = B · Phase Shift ---> Phase shift is distance from y-axis to max
- D (vertical shift) = (max + min)/2
D = (max + min)/2 = (3 - 11)/3 = -4
A = max - D = 3 - (-4) = 7
Period = 9π/4 - π/4 = 8π/4 = 2π
B = Period/2π = 2π/2π = 1
Phase Shift = π/4 - 0 = π/4
C = B · Phase Shift = 1 · π/4 = π/4
Equation:
y = 7 cos (1·x - π/4) + (-4)