If the fundamental period of function fx=sinx+cos4-a2x   is   4π, then the value of a is I are

Period  of sinx  is  2π  and  period  of cos4-a2x   is  2π4-a2.⇒  LCM2π,2π4-a2=4π  giveni.e.,    4-a2=p2  where  p=1,3Hence  a2=154,74,  a= ±152,±72