what is the equation of the function below? * make sure you have a y= in your equation ex: y=12cos(2pi/3x)+5…

what is the equation of the function below? * make sure you have a y= in your equation ex: y=12cos(2pi/3x)+5 no spaces!!! y=40cos(pi/40x)+20 keep trying!
Answer
Explanation:
Step1: Determine the amplitude
The amplitude $A$ is half the vertical distance between the maximum and minimum values. The maximum value is 60 and the minimum is - 20. So $A=\frac{60 - (-20)}{2}=\frac{80}{2}=40$.
Step2: Determine the vertical shift
The vertical - shift $D$ is the average of the maximum and minimum values. So $D=\frac{60+( - 20)}{2}=\frac{40}{2}=20$.
Step3: Determine the period
The period $T$ is the horizontal distance between two consecutive maxima. Here, $T = 80$. The formula for the period of a cosine function $y = A\cos(Bx)+D$ is $T=\frac{2\pi}{B}$. Solving for $B$ when $T = 80$, we get $B=\frac{2\pi}{T}=\frac{2\pi}{80}=\frac{\pi}{40}$.
Answer:
$y = 40\cos(\frac{\pi}{40}x)+20$