f(x)=2(1+cos2x)/2+√2sin2x+a²
=√3sin2x+cos2x+1+a²
=2(sin2x*√3/2+cos2x*1/2)+a²+1
=2(sin2xcosπ/6+cos2xπ/6)+a²+1
=2sin(2x+π/6)+a²+1