Answer:
3 units
Explanation:
The period of a wave is the time taken to complete a cycle of motion of the wave
In the given figure, the graduations of the x-axis, which is the usually time axis = 1 unit
At the origin, (0, 0), the vertical displacement of the wave = 0
The maximum value of the wave function is between x = 0 and x = 1
The minimum value of the wave function is between x = 2 and x = 3
At the point (3, 0) the value of the wave function is again 0, and a cycle of the wave is completed
Therefore, the period of the wave = 3 units of the x-variable