To find the unit of frequency.
Explanation:
The SI unit of frequency is Hertz (Hz). It is named after Heinrich Hertz.
It is equivalent to
[tex]\begin{gathered} frequency\text{ =}\frac{1}{time\text{ period}} \\ 1\text{ Hz}=\frac{1}{s} \\ =s^{-1} \end{gathered}[/tex]