Ex 3.3, 10 - Chapter 3 Class 11 Trigonometric Functions
Last updated at May 29, 2018 by Teachoo
Transcript
E 3.3, 10 Prove that sin ( + 1) sin ( + 2) +cos ( + 1) cos ( + 2) =cos Taking L.H.S. We know that cos ( A B) = cos A cos B + sin A sin B Hence A = (n + 1)x ,B = (n + 2)x Hence sin ( + 1) sin ( + 2) +cos ( + 1) cos ( + 2) = cos [ (n + 1)x (n + 2)x ] = cos [ nx + x nx 2x ] = cos [ nx nx x 2 x ] = cos (0 x ) = cos ( x) = cos x = R.H.S. Hence , L.H.S. = R.H.S. Hence proved
Ex 3.3
Ex 3.3, 1
Ex 3.3, 2
Ex 3.3, 3
Ex 3.3, 4 Important
Ex 3.3, 5 Important
Ex 3.3, 6
Ex 3.3, 7
Ex 3.3, 8 Important
Ex 3.3, 9
Ex 3.3, 10 You are here
Ex 3.3, 11 Important
Ex 3.3, 12
Ex 3.3, 13
Ex 3.3, 14
Ex 3.3, 15
Ex 3.3, 16
Ex 3.3, 17
Ex 3.3, 18 Important
Ex 3.3, 19
Ex 3.3, 20
Ex 3.3, 21 Important
Ex 3.3, 22
Ex 3.3, 23 Important
Ex 3.3, 24
Ex 3.3, 25
Chapter 3 Class 11 Trigonometric Functions
Serial order wise
About the Author
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.