JEE MATHEMATICS MCQ: COMPLEX NUMBERS

1 Easy

1 of 1

Application +4 | -1

z+\frac{1}{z}=2 \cos \theta, z \in \mathbf{C}

then

z^{2 n}-2 z^n \cos (n \theta)

is equal to

View answer and explanation

Correct option: C

-1

Option C (-1) is correct because after substituting

z = \cos \theta \pm i \sin \theta

into the expression and simplifying, the result is -1.

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