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  1. Chapter 3 Class 11 Trigonometric Functions
  2. Serial order wise

Transcript

Ex 3.2, 1 Find the values of other five trigonometric functions if cos⁑π‘₯ = – 1/2 , x lies in third quadrant. Since x is in lllrd Quadrant sin and cos will be negative But tan will be positive Given cos x = (βˆ’1)/2 We know that sin2 x + cos2 x = 1 sin2 x + ((βˆ’1)/2)^2 = 1 sin2 x + 1/4 = 1 sin2 x = 1 – 1/4 sin2 x = (4 βˆ’ 1)/4 sin2 x = (4 βˆ’1)/4 sin2x = 3/4 sin x = ±√(3/4) sin x = Β± √3/2 Since x is in lllrd Quadrant sin x is negative lllrd Quadrant ∴ sin x = βˆ’βˆšπŸ‘/𝟐 tan x = sin⁑π‘₯/cos⁑π‘₯ = (βˆ’βˆš3/2)/((βˆ’1)/2) = (βˆ’βˆš3)/2 Γ— 2/(βˆ’1) = βˆšπŸ‘ cosec x = 1/sin⁑π‘₯ = 1/((βˆ’βˆš3)/2) = (βˆ’πŸ)/βˆšπŸ‘ sec x = 1/cos⁑π‘₯ = 1/((βˆ’1)/2) = (βˆ’2)/1 = βˆ’2 cot x = 1/tan⁑π‘₯ = 𝟏/βˆšπŸ‘

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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.