Respuesta :
Answer:
2pi/5
Step-by-step explanation:
The only thing in this equation that affect the period is the '5' in front of the 'x'
cos period is usually 2pi
this is compressed by 5
period = 2pi/ 5
General equation
- y=Acos(Bx+C)+D
Our Equation
- y=-4cos(5x-9)-7
On comparing
- A=-4
- B=5
- C=-9
- D=-7
Now
Period
- 2π/B
- 2π/5