The answer is: [tex] 2 seconds [/tex]
The explanation for this answer is shown below:
1. By definition, the amount of second required for the pendulum to move from its resting position and return, is the period.
2. As you can see in the graph attached in the exercise, the wave interval is repeating every two units of x (or [tex] 2 seconds [/tex]).
3. Therefore, the period is [tex] 2 seconds [/tex].
