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

Last updated at Dec. 16, 2024 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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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo