Last updated at May 29, 2018 by Teachoo

Transcript

Misc 12 Prove 9π/8 – 9/4 sin-1 1/3 = 9/4 sin-1 (2√2)/3 Taking L.H.S. 9π/8 – 9/4 sin-1 1/3 = 9/4 (π/(2 )−"sin−1 " 1/3) = 9/4 "cos−1 " 1/3 Let a = "cos−1" 1/3 cos a = 1/3 Now, sin2 a = 1 – cos2 a sin a = √(1−cos2 𝑎) =√(1−(1/3)^2 ) "=" √(1−1/9) "=" √((9 − 1)/9) "=" √(8/9) "=" √((4 × 2)/32) " =" √((22 × 2)/32) "=" (√(2^2 ) × √2)/√(3^2 ) "=" (2 √2)/3 ∴ "sin a =" (2 √2)/3 a = sin-1 ((2 √2)/3) Hence, "cos−1 " 1/3 = a = sin-1 ((2 √2)/3) Now, From (1) 9π/8 – 9/4 sin-1 1/3 = 9/4 "cos−1 " 1/3 Putting value = 9/4 sin-1 ((2 √2)/3) Hence, 9π/8 – 9/4 sin-1 1/3 = 9/4 sin-1 ((2 √2)/3) Hence proved

Chapter 2 Class 12 Inverse Trigonometric Functions

Ex 2.1, 5
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Ex 2.1, 8 Important

Ex 2.1, 12 Important

Ex 2.1, 14 Important

Example 5 Important

Example 8 Important

Ex 2.2, 12 Important

Ex 2.2, 15 Important

Ex 2.2, 19 Important

Ex 2.2, 21 Important

Example 10 Important

Example 12 Important

Example 13 Important

Misc. 2 Important

Misc. 7 Important

Misc. 10 Important

Misc. 11 Important

Misc 12 Important You are here

Misc. 17 Important

Class 12

Important Question for exams Class 12

- Chapter 1 Class 12 Relation and Functions
- Chapter 2 Class 12 Inverse Trigonometric Functions
- Chapter 3 Class 12 Matrices
- Chapter 4 Class 12 Determinants
- Chapter 5 Class 12 Continuity and Differentiability
- Chapter 6 Class 12 Application of Derivatives
- Chapter 7 Class 12 Integrals
- Chapter 8 Class 12 Application of Integrals
- Chapter 9 Class 12 Differential Equations
- Chapter 10 Class 12 Vector Algebra
- Chapter 11 Class 12 Three Dimensional Geometry
- Chapter 12 Class 12 Linear Programming
- Chapter 13 Class 12 Probability

About the Author

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.