y=sin^4(x)+2根号3sinxcosx-cos^4(x) =sin^4(x)-cos^4(x)+2根号3sinxcosx =(sin²x+cos²x)(sin²x-cos²x)+2根号3sinxcosx =2根号3sinxcosx-cos2x =√3sin2x-cos2x =2sin(2x-π/6) 最小正周期π和...