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Evaluate cos 48°  cos 42° − sin 48° sin 42°

Evaluate cos 48°  cos 42° − sin 48° sin 42° - Teachoo - CBSE Class 10

 

Note : This is similar to Ex 8.3, 2 (ii) of NCERT – Chapter 8 Class 10

Check the answer here https://www.teachoo.com/1774/531/Ex-8.3--1---Evaluate-(i)-sin-18---cos-72-(ii)-tan-26-cot-64/category/Ex-8.3/

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Question 24 (OR 2nd question) Evaluate cos 48° cos 42° − sin 48° sin 42° cos 48° cos 42° – sin 48° sin 42° = cos (90 – 42)° cos (90 – 48)° – sin 48° sin 42° = sin 42° sin 48° – sin 48° sin 42° = 0 (cos (90 – θ) = sin θ )

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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.