2.设函数f(x)=[tgx+ctgx]分之[sin2x+cos2x]<1>求的f(x)最小正周期写一下详细过程

热心网友

no ,you are wrong the correct answer is 由tgx=sinx\cosx, ctgx=cosx\sinx .tgx+ctgx=sinx\cosx +cosx\sinx=1\sinxcosx原式=(sin2x+cos2x)*2\sin2x=2(sin2x*sin2x+sin2x*cos2x)sin2x*sin2x=(1-cos4x)\2sin2x*cos2x=sin4x\2原式=2(1/2+1/2(sin4x-cos4x)=1+1*sina(4x-n/4)*2故最小正周期为2n/4=n/2

热心网友

由tgx=sinx\cosx, ctgx=cosx\sinx . tgx+ctgx=sinx\cosx +cosx\sinx=1\sinxcosx 原式=(sin2x+cos2x)*1\2sin2x =1\2(sin2x*sin2x+sin2x8cos2x) sin2x*sin2x=(1-cos4x)\2 sin2x*cos2x=sin4x\2 原式=1/2(1/2+1/2(sin4x-cos4x) =1/4+1/4*sina(4x-n/4)*2 故最小正周期为2n/4=n/2