=(1/4)(1/2)(1/2) ∫(1-cos4t)(1-cos2t)dt
=(1/16) ∫(1-cos4t-cos2t+cos4tcos2t)dt
=t/16-(sin4t)/64-(sin2t)/32+(1/16)(1/2)∫(cos6t+cos2t)dt
=t/16-(sin4t)/64-(sin2t)/32+(1/192)*(sin6t)+(sin2t)/64+C