Answer: 5
Step-by-step explanation:
One root (aka x intercept) is at x = 0
The next root over isn't clear, but luckily we can skip over it and see the next root after that is x = 5
After this point, the curve repeats itself. This means the period is 5 units.
The graph repeats itself every 5 units, aka the cycle is 5 time units long.