Let w = cos and α = w + w 2 + w 4 and β = w 3 + w 5 + w 6 . αβ equals :

Mathematics · JEE Advanced · NTA Exams — Complex Numbers and Quadratic Equations

Let w = cos and α = w + w² + w⁴ and
β = w³ + w⁵ + w⁶.
αβ equals :

1. –1
2. 0
3. 1
4. 2

Answer

(D) 2

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