Q.
If z and ω are two complex numbers such that ∣zω∣=1 and arg(z)−arg(ω)=23π, then arg(1+3zω1−2zˉω) is :
(Here arg(z) denotes the principal argument of complex number z )
As ∣zω∣=1 ⇒∣f∣z∣=r, then ∣ω∣=r1
Let arg(z)=θ ∴arg(ω)=(θ−23π)
So, z=reiθ ⇒Zˉ=rei(−θ) ω=r1ei(θ−23π)
Now, consider 1+3zˉω1−2zˉω=1+3e(−23π)1−2ei(−23π)=(1+3i1−2i) =(1+3i)(1−3i)(1−2i)(1−3i)=−21(1+i) ∴ prin arg(1+3zˉω1−2zˉω) = prin arg(1+3zˉω1−2zˉω) =(−21(1+i)) =−(π−4π)=4−3π