JEE MainMathematicsComplex NumbersMCQ+4 / −1
If are the distinct roots of the equation x2 - x + 1 = 0, then is equal to :
- A2
- B-1
- C0
- D1
View written solutionFree
Correct answer: D
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We are given that are the distinct roots of
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Solve the quadratic: So the roots are These are complex cube roots of unity other than .
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From for a root , we get Multiplying by , Hence Therefore,
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Reduce the exponents modulo : So, Thus
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Since and , Therefore,
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Using Vieta's formulas for we have Hence,
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Therefore,
So the correct option is D.
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