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Question 12 - NCERT Exemplar - MCQ - Chapter 8 Class 10 Introduction to Trignometry

Last updated at May 29, 2023 by

If sin A + sin 2 A = 1, then the value of the expression (cos 2 A + cos 4 A) is

(A) 1  (B) 1/2   (C) 2   (D) 3

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Question 12 If sin A + sin2 A = 1, then the value of the expression (cos2 A + cos4 A) is (A) 1 (B) 1/2 (C) 2 (D) 3 Given sin A + sin2 A = 1 sin A = 1 − sin2 A sin A = cos2 A Now, cos2 A + cos4 A = cos2 A + (cos2 A) 2 Putting cos2 A = sin A = sin A + sin2 A Given sin A + sin2 A = 1 = 1 So, the correct answer is (A)

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