Example 15 - Chapter 3 Class 11 Trigonometric Functions
Last updated at Dec. 16, 2024 by Teachoo
Last updated at Dec. 16, 2024 by Teachoo
Example 15 Prove that cos (ฯ/4+๐ฅ) + cos (ฯ/4โ๐ฅ) = โ2 cos ๐ฅ Solving L.H.S. cos (ฯ/4+๐ฅ) + cosโก(ฯ/4โ๐ฅ) = 2 cos ((ฯ/4 " + " ๐ฅ + ฯ/4 " โ " ๐ฅ )/2) cos ((ฯ/4 " + " ๐ฅ โ (ฯ/4 " โ " ๐ฅ) )/2) = ๐ ๐๐๐โก๐/๐ ๐๐๐โก๐ = 2 ร 1/โ2 cosโก๐ฅ = โ๐ ๐๐๐โก๐ = R.H.S.
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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