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Ex 2.1, 5 - Chapter 2 Class 12 Inverse Trigonometric Functions
Last updated at Feb. 13, 2020 by Teachoo
Transcript
Ex 2.1, 5 Find the principal value of cos−1 (−1/2) Let y = cos−1 (−1/2) cos y = −1/2 cos y = cos (2π/3). Range of principal value of cos−1 is [0 , 𝜋] Hence, the principal value is 𝟐𝝅/𝟑. Rough We know that cos 60° = 1/2 θ = 60° = 60° × 𝜋/180 = 𝜋/3 Since (−1)/2 is negative Principal value is 𝜋 – θ i.e. π −𝜋/3 = 2𝜋/3
Chapter 2 Class 12 Inverse Trigonometric Functions
Serial order wise
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