Which of the following are identities? A) sin^2x - cos^2x = 1. B) sin^2x = 1 - cos^2x. C) tan^2x = 1 + sec^2x. D) cot^2x = csc^2x - 1

Question

Mathematics

Isiah York

14 March, 18:19

Which of the following are identities? A) sin^2x - cos^2x = 1. B) sin^2x = 1 - cos^2x. C) tan^2x = 1 + sec^2x. D) cot^2x = csc^2x - 1

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Answers (1)

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Nayeli Villanueva · Answer 1

B) sin² x = 1 - cos² x

sin² x + cos² x = 1 (correct)

D) cot² x = csc² x - 1

cos²x / sin²x = 1/sin²x - 1 = (1-sin²x) / sin²x = cos²x/sin²x

Identities are B) and D).