Question

If `omega(!=1)` is a cube root of unity, and `(1""+omega)^7=""A""+""Bomega` . Then (A, B) equals (1) (0, 1) (2) (1, 1) (3) (1, 0) (4) `(-1,""1)`
A. 0,1
B. 1,1
C. 1,2
D. `-1,1`

Answer 1

Correct Answer - B
`(1+omega)^7=(1+omega)(1+omega)^6`
`=(1+omega)(-omega^2)^6=1+omega`
`rArr " "A+Bomega=1+omega`
`rArr" "A=1,B=1`