Question
Question: If w is a cube root of unity, then(3 + 5w + 3w<sup>2</sup>)<sup>2</sup> + (3 + 3w + 5w<sup>2</sup>)<...
If w is a cube root of unity, then(3 + 5w + 3w2)2 + (3 + 3w + 5w2)2 is equal to
A
4
B
0
C
– 4
D
None of these
Answer
– 4
Explanation
Solution
Sol. We known (1 + w + w2) = 0
so, (– 3w + 5w)2 + (– 3w2 + 5w2)2= 4w2 + 4w = – 4