Period of f(x)=sgn([x]+[−x]) is equal to (where [.] denotes greatest integer function)
1
2
3
does not exist
x+-x =0 if x∈Z
=-1 if x∉ Z
Now fx =Sgnx+-x =Sgn0 =0 if x∈Z
= Sgn -1 =-1 if x ∉Z
therefore fx period is 1