设函数f x =asinwx+bcosws(w

设函数f x =asinwx+bcosws(w√(a^2+b^2)=8
b/a=tan(2π/3)=-√3==>b=-√3a
a^2+b^2=64==>a^2=16
∵ab=4√3
∴f(x)=8sin(-2x+2π/3)
(2)解析：∵f(x)=8sin(-2x+2π/3)=8sin(2x-2π/3+π)=8sin(2x+π/3)
单调递增区：2kπ-π/2