Solution:
Given:
[tex]d=5sin(\frac{\pi t}{4})[/tex]
Comparing the equation to the wave equation;
[tex]\begin{gathered} y=Asin(\omega t\pm kx) \\ d=5sin(\frac{\pi}{4}t) \\ \\ Hence, \\ \omega=\frac{\pi}{4} \\ \\ But\text{ }\omega=2\pi f \\ 2\pi f=\frac{\pi}{4} \\ f=\frac{\pi}{8\pi} \\ f=\frac{1}{8} \end{gathered}[/tex]
Therefore, the frequency is;
[tex]\frac{1}{8}[/tex]
