Verified Answer :

it's just 1/8, no pi included (if you're on APEX)

Answer : Frequency, \(u=\dfrac{1}{8}\ Hz\)

Explanation :

The equation of a particle executing SHM is given by :

\(y=A\ sin\omega t\).........(1)

Where,

y is the displacement

A is the amplitude of the wave

\(\omega\) is the angular frequency of the wave

t is the time

The given equation is :

\(y=5\ sin(\dfrac{\pi}{4})\ t\)............(2)

Comparing equation (1) and (2)

\(\because\ \omega=2\pi u\)

So,

\(\dfrac{\pi}{4}=2\pi u\)

\(u=\dfrac{1}{8}\ Hz\)

Hence, this is the required solution.