2sinwx×cosxwx=sin2wx
2cos^2wx=cos2wx+1
f(x)=cos2wx+sin2wx+2=根号2*sin(2wx+π/4)+2
T=π/2
w=2
f(x)=根号2*sin(4x+π/4)+2
函数最大值时
x=k*π/2+π/16