Question
Question: If w is a cuberoot of unity then (1 + w – w<sup>2</sup>)<sup>7</sup> is equal to...
If w is a cuberoot of unity then (1 + w – w2)7 is equal to
A
128 w
B
– 128 w
C
128 w2
D
– 128 w2
Answer
– 128 w2
Explanation
Solution
(– w2 – w2)7 Q 1 + w + w2 = 0 = –128w2