Complex Numbers And Quadratic Equations question 307
Question: If 1, $ \omega ,{{\omega }^{2}} $ are the cube roots of unity then $ {{\omega }^{2}}{{(1+\omega )}^{3}}-(1+{{\omega }^{2}})\omega = $ [Orissa JEE 2005]
Options:
A) 1
B) -1
C) i
D) 0
Show Answer
Answer:
Correct Answer: D
Solution:
$ {{\omega }^{2}}{{(1+\omega )}^{3}}-(1+{{\omega }^{2}})\omega ={{\omega }^{2}}{{(-{{\omega }^{2}})}^{3}}-\omega (-\omega ) $ = $ -{{\omega }^{2}}+{{\omega }^{2}}=0 $ .
BETA
