Complex Numbers And Quadratic Equations question 295

Question: If $ \omega $ is a complex cube root of unity, then the value of $ {{\omega }^{99}}+{{\omega }^{100}}+{{\omega }^{101}} $ is [Pb. CET 2004]

Options:

A) 1

B) - 1

C) 3

D) 0

Show Answer

Answer:

Correct Answer: D

Solution:

$ {{\omega }^{99}}+{{\omega }^{1\omega }}+{{\omega }^{101}} $ = $ {{\omega }^{99}}[1+\omega +{{\omega }^{2}}] $ [Since $ 1+\omega +{{\omega }^{2}}=0,{{\omega }^{3}}=1 $ ] = 0.