NTA Abhyas JEE Main2020MathematicsFunctionsPractice
If sin - 1 ⁡ x 4 - 2 sin - 1 ⁡ x 2 + 1 ≤ 0 , then (where, . represents the greatest integral part of x )
Options
- Ax ∈ sin 1 , sin 2 ∪ - 1 , 0
- Bx ∈ - sin 1 , 0 ∪ sin 1 , 1
- Cx ∈ sin 1 , 1 ∪ - sin 1 , 0
- Dx ∈ - sin 1 , sin 2
Correct answer
C. x ∈ sin 1 , 1 ∪ - sin 1 , 0
Step-by-step solution
sin - 1 x 2 - 1 2 ≤ 0 ⇒ sin - 1 x 2 - 1 = 0 ⇒ sin - 1 x = 1 , - 1 ⇒ 1 ≤ sin - 1 x < 2 or - 1 ≤ sin - 1 < 0 but sin - 1 x ∈ - π 2 , π 2 ∴ 1 ≤ sin - 1 x ≤ π 2 or - 1 ≤ sin - 1 x < 0 ⇒ x ∈ - sin 1 , 0 ∪ sin 1 , 1