Example 17 - Chapter 3 Class 11 Trigonometric Functions
Last updated at May 29, 2018 by Teachoo
Transcript
Example 17 Prove that sin 5x 2sin 3x + sin x / 5x x = tan x Taking L.H.S. sin 5x + sin x 2sin 3x / 5x x = (sin 5x + sin x ) 2sin 3x / 5x x Solving numerator and denominator separately Taking R.H.S sin 5x + sin x 2sin 3x / 5x x Putting values = (2 sin 3 cos 2 2 sin 3 )/( 2 sin 3 sin 2 ) = (2 sin 3 (cos 2 1) )/( 2 sin 3 sin 2 ) = ( (cos 2 1) )/( sin 2 ) = ( (cos 2 1) )/sin 2 = ( 1 cos 2 )/sin 2 = (1 (1 2 sin2 ) )/(2 cos sin ) = (0 + 2 sin2 )/(2 cos sin ) = (2 sin2 )/(2 cos sin ) = sin /cos = tan x = R.H.S. Hence L.H.S. = R.H.S. Hence proved
Examples
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Example 11
Example 12
Example 13
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Example 16
Example 17 You are here
Example 18
Example 19
Example 20
Example 21
Example 22
Example 23
Example 24 Important
Example 25
Example 26
Example 27 Important
Example 28 Important
Example 29
Chapter 3 Class 11 Trigonometric Functions
Serial order wise
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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.