Download the app

Questions  

If 1,ω,.....ωn-1 are the nth roots of unity, then value of 12-ω+12-ω2+...+12-ωn-1 equals

a
12n-1
b
n(2n-1)2n+1
c
(n-2)2n-12n-1
d
none of these

detailed solution

Correct option is D

We know that1x−1+1x−ω+1x−ω2+⋯+1x−ωn−1=nxn−1xn−1Putting x=2, we get               12−ω+12−ω2+⋯+12−ωn−1=n2n−12n−1

Talk to our academic expert!

+91

Are you a Sri Chaitanya student?


Similar Questions

Let z1 and z2 be nth roots of unity which subtend a right angle at the origin. Then n must be of the form 


phone icon
whats app icon