JEE Main202117 Mar 2021Morning ShiftMathematicsLimitsActual
The value of lim x → 0 + cos - 1 x - [ x ] 2 · sin - 1 x - [ x ] 2 x - x 3 , where x denotes the greatest integer ≤ x is:
Options
- Aπ
- B0
- Cπ 4
- Dπ 2
Correct answer
D. π 2
Step-by-step solution
Given L = lim x → 0 + cos - 1 x - [ x ] 2 · sin - 1 x - [ x ] 2 x - x 3 ∵   x ∈ [ 0 , 1 ) ⇒ x = 0 Then L = lim x → 0 + cos - 1 x 1 - x 2 × lim x → 0 + sin - 1 x x L = π 2 × lim x → 0 + 1 1 - x 2     Apply L'Hospital rule for  0 0  form L = π 2