Question 11 - NCERT Exemplar - MCQ - Chapter 8 Class 10 Introduction to Trignometry

Last updated at April 16, 2024 by

If ∆ABC is right angled at C, then the value of cos (A + B) is

(A) 0   (B) 1   (C) 1/2    (D) √3/2

Slide17.JPG

Slide18.JPG

Go Ad-free

Transcript

Question 11 If ∆ABC is right angled at C, then the value of cos (A + B) is (A) 0 (B) 1 (C) 1/2 (D) √3/2 Given ∠ C = 90° Now, By Angle sum property in Δ ABC ∠ A + ∠ B + ∠ C = 180° ∠ A + ∠ B + 90° = 180° ∠ A + ∠ B = 180° − 90° ∠ A + ∠ B = 90° Now, cos (A + B) = cos 90° = 0 So, the correct answer is (A)

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 and Computer Science at Teachoo