Question

What is the period of `f(t)=cos 5 t`?

Answer 1

`T=(2pi)/5=72^@`

Explanation:

For any general cosine function of the form `f(t)=AcosBt`, the amplitude is `A` and represents the maximum displacement from the t-axis, and the period is `T=(2pi)/B` and represents the number of units on the `t` axis for a complete cycle or wavelength of the graph to pass by.

So in this particular case, the amplitude is `1`, and the period is `T=(2pi)/5=72^@`,

since by the conversion factor, `360^@=2pirad`.

The graph is plotted below :

graph{cos(5x) [-2.735, 2.74, -1.368, 1.368]}