The position of a mass that is oscillating on a spring is given by (15.9 cm) because [(2.64 s-1) t].
What is frequency of this motion?

You should know that:



That is periodic time is the reciprocal of frequency.

So, find the periodic time, then take the reciprocal to get the frequency.

Just to be sure, is this your equation?:

Yeah, I was wondering because I have seen



where, as you pointed out,