1,将函数写成f(x)=Asin(ωx+ψ)+k(A>0,ω>0,|ψ|<π/2)的形式
2求f(x)的周期
f(x)=sin²x+sin2x+3cos²x=cos2x+sin2x+2=√2 sin(2x+π/4)+2
T=π