y=tanx+1/tanx的周期是π/2,

问题描述:

y=tanx+1/tanx的周期是π/2,

y=sinx/cosx+cosx/sinx=1/(cosxsinx)=1/(sin2x/2)=2sin2x T=2π/2=π

答案有误.
y=sinx/cosx+cosx/sinx
=(sin²x+cos²x)/(sinxcosx)
=1/(sinxcosx)
=2/(2sinxcosx)
=2/sin2x
所以 T=2π/2=π.