求函数Y＝SIN＾6X＋COS＾6X的最大，小值。判断是否周期函数。加过程，急用，那个是sin6次方x

求函数Y＝SIN＾6X＋COS＾6X的最大，小值。判断是否周期函数。加过程，急用，那个是sin6次方x

8+(3/2
=5/4*(4sinx*cosx)^2
=1-(3/8)cos4x

最小周期T=2π/4)sin^2 2x
=1-(3/4)(1-cos4x)/4=π/f(x)=(sin^2x+cos^2x)(sin^4x-sin^2x*cos^2x+cos^4x)
=sin^4x-sin^2x*cos^2x+cos^4x
=(sin^2x+cos^2x)^2-3sin^2x*cos^2x
=1-3/

y=(sinx)^6+(cosx)^6=[(sinx)^2+(cosx)^2][(sinx)^4-(sinxcosx)^2+(cosx)^4] =[(sinx)^2+(cosx)^2]^2-3(sinxcosx)^2 =-3(sinxcosx)^2 =-(3/4)(sin2x)^2 =(3/8)(1-cos4x) t=2兀/4=兀/2