Answer:
4Hz
Step-by-step explanation:
Standard form of a sine or cosine function,
y = acos(b(x+c))
where a is the amplitude, b is the value to find the period. and c is the phase shift.
Period = \frac{2\pi}{b}
From the equation given in the question,
We can see:
Amplitude = 3,
Period = \frac{2\pi}{8\pi} = 1 / 4
Phase Shift = 1 / 16
Now we want to find the frequency.
Frequency = 1 / Period
= 1 / (1/4)
= 4Hz