If is a non-real root of , find the value of .
Answer and explanation
Correct answer: D.
- Step 1: The complex cube roots of unity satisfy . Because is a non-real root, , so it satisfies and .
- Step 2: Expand the product: .
Answer
.
Why not the others: The value erroneously assumes that one of the factors is zero; the value equates but omits adding ; the value incorrectly evaluates and as real ones.
Practise more Vectors in 3D Space and Complex Numbers.
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