求复数z=tanθ-i(π/2

问题描述:

求复数z=tanθ-i(π/2

z=tanθ-i
=-cot(π/2+θ)-i
=-1/sin(π/2+θ)(cos(π/2+θ)+isin(π/2+θ))
=1/sin(π/2+θ)(cos(π+π/2+θ)+isin(π+π/2+θ))
=1/sin(π/2+θ)(cos(θ-π/2)+isin(θ-π/2))π/2