Answer:
3
Explanation:
Period of a function is the period after which the function attains the same value
in the graph attached with this problem we can see that
f(0)=1
the value of x for which function f(x) attains the value 1 again is at
x=3
f(3)=1
similarly , we see
f(6)=1 , f(9)=1
Hence we see that after every increased value of x by 3 units , we attain the same value of function . hence the period of the function is 3