JEE Main202311 Apr 2023Evening ShiftMathematicsFunctionsActual
The domain of the function f x = 1 x 2 - 3 x - 10 is (where [ x ] denotes the greatest integer less than or equal to x )
Options
- A( - ∞ , - 3 ] ∪ ( 5 , ∞ )
- B( - ∞ , - 2 ) ∪ [ 6 , ∞ )
- C( - ∞ , - 2 ) ∪ ( 5 , ∞ )
- D( - ∞ , - 3 ] ∪ [ 6 , ∞ )
Correct answer
B. ( - ∞ , - 2 ) ∪ [ 6 , ∞ )
Step-by-step solution
Given: f x = 1 x 2 - 3 x - 10 For f x to be defined, x 2 - 3 x - 10 > 0 ⇒ x - 5 x + 2 > 0 ⇒ x < - 2   &   x > 5 ⇒ x < - 2   &   x ≥ 6 So, domain is - ∞ , - 2 ∪ [ 6 , ∞ ) .