Example 6 - Chapter 3 Class 11 Trigonometric Functions
Last updated at Dec. 8, 2016 by Teachoo
Transcript
Example 6 If cos𝑥 = – 3/5 , x lies in third quadrant, find the values of other five trigonometric functions. Since x is in lllrd Quadrant sin and cos will be negative But tan will be positive Given cos x = (−3)/5 We know that sin2 x + cos2 x = 1 sin2 x + ((−3)/5)^2 = 1 sin2 x + 9/25 = 1 sin2 x = 1 – 9/25 sin2 x = (25 − 9)/25 sin2x = 16/25 sin x = ±√(16/25) sin x = ± 4/5 Since, x is in lllrd Quadrant sin x is negative lllrd Quadrant ∴ sin x = −4/5 tan x = sin𝑥/cos𝑥 = (− 4/5)/(− 3/5) = (−4)/5 × 5/(−3) = 4/3 cosec x = 1/sin𝑥 = 1/(− 4/5) = (−5)/4 sec x = 1/cos𝑥 = 1/((−3)/5) = 5/(−3) = (−5)/3 cot x = 1/tan𝑥 = 1/(4/3) = 3/4
Examples
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Example 2
Example 3
Example 4
Example 5
Example 6 You are here
Example 7
Example 8
Example 9
Example 10
Example 11
Example 12
Example 13
Example 14
Example 15
Example 16
Example 17
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
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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.
