Question

What is the period of `f(t)=sin( 9 t)`?

Answer 1

`(2pi)/9` radians

Explanation:

For any general sine graph of form `y=AsinBt`, the amplitude is `A` and the period is given by `T=(2pi)/B` and represents the units on the t axis required for 1 complete cycle of the graph to pass by.

So in this particular case, `T=(2pi)/9`.

For verification purpose you may plot the actual graph :

graph{sin(9x) [-2.735, 2.74, -1.369, 1.366]}