NTA Abhyas JEE Main2020MathematicsInverse Trigonometric FunctionsPractice
The value of sin - 1 ⁡ sin ⁡ 17 + cos - 1 ⁡ cos ⁡ 10 is equal to
Options
- A27
- B- 27
- C17 - 5 π
- D9 π - 27
Correct answer
D. 9 π - 27
Step-by-step solution
sin - 1 ⁡ sin ⁡ 17 = sin - 1 ⁡ sin ⁡ 17 - 5 π + 5 π = 5 π - 17 cos - 1 ⁡ cos ⁡ 10 = cos - 1 ⁡ cos ⁡ 10 - 3 π + 3 π = cos - 1 ⁡ cos ⁡ 3 π + 10 - 3 π = cos - 1 ⁡ - cos ⁡ 10 - 3 π = π - cos - 1 ⁡ cos ⁡ 10 - 3 π = π - 10 - 3 π = 4 π - 10 Hence, sin - 1 ⁡ sin ⁡ 17 + cos - 1 ⁡ cos ⁡ 10 = 9 π - 27