The fundamental period of the function f(x)=4cos4x−π4π2−2cosx−π2π2 is equal to
π3
4π3
3π3
2π3
f(x)=1+cosx−π2π22−2cosx−π2π2
=1+cos2x−π2π2
Period of f(x)=π12π2=2π3