函数y=sin4次方x+2倍根3sinxcosx-cos4次方x的最小正周期和最小值

y=(sinx)^4+2√3sinxcosx-(cosx)^4=[(sinx)^4-(cosx)^4]+2√3sinxcosx =(sin^2x+cos^2x)(sin^2x-cos^2)x+√3sin2x=-cos2x+√3sin2x∴y=2sin(2x-π/6) 最小周期T=π ,最小值-2.令2x-π/6∈[-1/2*π+2kπ,1/2*π+2kπ]...