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

Last updated at April 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

Slide19.JPG

Slide20.JPG

Transcript

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)

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

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, Social Science, Physics, Chemistry, Computer Science at Teachoo.