已知函数f(x)=cos²x+√3sinxcosx-1/2.已知cos(β-α）=4/5,cos(β+α）=-3/5,0

已知函数f(x)=cos²x+√3sinxcosx-1/2.已知cos(β-α）=4/5,cos(β+α）=-3/5,0
已知函数f(x)=cos²x+√3sinxcosx-1/2.已知cos(β-α）=4/5,cos(β+α）=-3/5,0

已知函数f(x)=cos²x+√3sinxcosx-1/2.已知cos(β-α）=4/5,cos(β+α）=-3/5,0
f(x)=cos²x+√3sinxcosx-1/2
=1/2cos(2x)+√3/2sin(2x)
=sin(2x+π/6)
cos(β-α）=4/5,cos(β+α）=-3/5,∵0