Question
Question: If w is a cube root of unity, then the value of (1 + w – w<sup>2</sup>). (1 – w + w<sup>2</sup>) is...
If w is a cube root of unity, then the value of (1 + w – w2).
(1 – w + w2) is
A
1
B
0
C
2
D
4
Answer
4
Explanation
Solution
Sol. If 1 + w + w2 = 0
1 + w = – w2
1 + w2 = – w
= ( –2 w2) (–2w)
= 4 w3 = 4