NTA Abhyas JEE Main2020MathematicsLimitsPractice
The value of lim x → 1 - 2 π - 4 sin - 1 x 1 - x is equal to
Options
- Aπ
- B1 2 π
- Cπ 2
- D2 π
Correct answer
D. 2 π
Step-by-step solution
We have, lim x → 1 - π - 2 sin - 1 x 1 - x 2 = lim x → 1 - π - 2 sin - 1 x 1 - x × π + 2 sin - 1 x π + 2 sin - 1 x × 2 = lim x → 1 - 2 2 π 2 - sin - 1 x 1 - x π + 2 sin - 1 x = lim x → 1 - 2 2 cos - 1 x 1 - x ⋅ 1 2 π = lim θ → 0 + 2 2 θ 2 sin θ 2 ⋅ 1 2 π [Putting x = cos θ ] = 4 2 2 2 π = 2 π