Example 15 - Chapter 3 Class 11 Trigonometric Functions (Term 2)
Last updated at May 29, 2018 by Teachoo
Examples
Example 1
Example 2 Important
Example 3
Example 4
Example 5 Important
Example 6 Important
Example 7 Important
Example 8
Example 9 Important
Example 10
Example 11 Important
Example 12
Example 13
Example 14
Example 15 You are here
Example 16 Important
Example 17 Important
Example 18
Example 19
Example 20 Deleted for CBSE Board 2022 Exams
Example 21 Deleted for CBSE Board 2022 Exams
Example 22 Important Deleted for CBSE Board 2022 Exams
Example 23 Deleted for CBSE Board 2022 Exams
Example 24 Important Deleted for CBSE Board 2022 Exams
Example 25 Important
Example 26
Example 27 Important
Example 28 Important
Example 29 Important
Chapter 3 Class 11 Trigonometric Functions (Term 2)
Serial order wise
- Ex 3.1
- Ex 3.2
- Ex 3.3
- Ex 3.4
-
Examples
- Miscellaneous
Transcript
Example 15 Prove that cos (𝜋/4 + x) + cos (𝜋/4 − 𝑥) = root(2) cos 𝑥 Solving L.H.S : cos (𝜋/4 + x) + cos (𝜋/4 − 𝑥) Using 𝑐𝑜𝑠 𝐴+𝐵+𝑐𝑜𝑠 𝐴−𝐵=2𝑐𝑜𝑠 𝐴𝑐𝑜𝑠 𝐵 cos π4+π+cos π4−x=2 cos π4 cos𝑥 = 2 × 1 2 cos𝑥 = 2 cos 𝑥 = R.H.S ∴ L.H.S = R.H.S Hence, Proved
