1. Chapter 2 Class 12 Inverse Trigonometric Functions
  2. Serial order wise
  3. Ex 2.2
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Ex 2.2, 13 (MCQ) - Chapter 2 Class 12 Inverse Trigonometric Functions

Last updated at Dec. 16, 2024 by Teachoo

Transcript

Ex 2.2, 13 Find the values of cos−1(cos 7π/6) is equal to (A) 7π/6 (B) 5𝜋/6 (C) 𝜋/3 (D) 𝜋/6 Let y = cos−1 (cos 7π/6) cos y = cos (7π/6) cos y = cos (210°) Since Range of of cos−1 is [0, π] i.e. [0° ,180°] Hence, y = 210° not possible Now, cos y = cos (210°) cos y = cos (360° – 150°) cos y = cos (150°) cos y = cos (𝟓𝝅/𝟔) Hence, y = 𝟓𝝅/𝟔 Which is in the range of principal value of cos-1 i.e. [0, π] Hence , cos −1 (cos 7π/6) = 5𝜋/6 Thus, option (B) is correct
  1. Chapter 2 Class 12 Inverse Trigonometric Functions
  2. Serial order wise

    3. Ex 2.2

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Chapter 2 Class 12 Inverse Trigonometric Functions
Serial order wise

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo