Period of cosx×cos(120-x)×cos(120+x)? Share with your friends Share 1 Brijendra Pal answered this HI, y = cosx cos120-xcos120+xNow we know that cosA-BcosA+B= cos2A-sin2Bso here cos120-xcos120+x= cos2120-sin2x= 14-sin2x= 14-1+cos2x=cos2x-34 so y = cosx cos2x-34= 144cos3x-3cosx= cos3x4so period = 2π3 8 View Full Answer
