Class 11Mathematics1 Complex Numbers and Quadratic Equations: Complex NumbersDe Moivre's theorem and Roots of unity
MediumIf $\sqrt{x}+\frac{1}{\sqrt{x}}=2 \cos \theta$,then $x^6+x^{-6}=$
- A$2 \cos 6 \theta$
- B$2 \cos 12 \theta$
- C$2 \cos 3 \theta$
- D$2 \sin 3 \theta$
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