Check sibling questions

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

Last updated at May 29, 2023 by

If cos (α + β) = 0, then sin (α – β) can be reduced to

(A) cos β   (B) cos 2β   (C) sin α   (D) sin 2α

Slide11.JPG

Slide12.JPG

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Book a free demo

Transcript

Question 8 If cos (α + β) = 0, then sin (α – β) can be reduced to (A) cos β (B) cos 2β (C) sin α (D) sin 2α Given that cos (α + β) = 0 cos (α + β) = cos 90° Comparing angles α + β = 90° α = 90° − β Now, sin (α – β) = sin (90° − β − β) = sin (90° − 2β) Using cos A = sin (90° − A) = cos 2β So, the correct answer is (B)

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 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.