NTA Abhyas JEE Main2020MathematicsInverse Trigonometric FunctionsPractice
The value of 2 sin - 1 4 5 + 2 sin - 1 5 13 + 2 sin - 1 16 65 is equal to
Options
- A3 π 2
- Bπ 2
- Cπ
- D2 π
Correct answer
C. π
Step-by-step solution
2 sin - 1 ⁡ 4 5 + sin - 1 ⁡ 5 13 + sin - 1 ⁡ 16 65 = 2 sin - 1 ⁡ 4 5 1 - 5 13 2 + 5 13 1 - 4 5 2 + 2 sin - 1 ⁡ 16 65 = 2 sin - 1 ⁡ 48 65 + 15 65 + 2 sin - 1 ⁡ 16 65 = 2 sin - 1 ⁡ 63 65 + sin - 1 ⁡ 16 65 = 2 cos - 1 ⁡ 16 65 + sin - 1 ⁡ 16 65   ∵ sin - 1 ⁡ x = cos - 1 ⁡ 1 - x 2 = π