Range of f(θ)=cos2⁡θcos2⁡θ+1+2sin2⁡θ is

f(θ)=cos2⁡θcos2⁡θ+1+2sin2⁡θ=cos4⁡θ+cos2⁡θ+sin2⁡θ+sin2⁡θ=cos4⁡θ+1+1−cos2⁡θ=cos2⁡θ−122+2−14=cos2⁡θ−122+74fmin. =74fmax.=14+74=2