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What does (cos θ + i sin θ)^−1 equal?
Asin θ − i cos θ
Bcos θ + i sin θ
C−cos θ − i sin θ
Dcos θ − i sin θ
Answer & Solution
Correct answer: D. cos θ − i sin θ
Using n = −1, the result is cos(−θ) + i sin(−θ), which equals cos θ − i sin θ.
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