NTA Abhyas JEE Main2020MathematicsFunctionsPractice
If f x = x 2 - x 2 x 2 - x 2 - 2 (where, ⋅ represents the greatest integer part of x ), then the range of f x is
Options
- A0 , 1
- B- 1 , 1
- C0 , ∞
- D0 , 1 3
Correct answer
D. 0 , 1 3
Step-by-step solution
We know that, x 2 - x 2 = x 2 ∴ f x = x 2 2 + x 2 = 2 + x 2 - 2 2 + x 2 = 1 - 2 2 + x 2 ∴ 0 ≤ x 2 < 1 ⇒ 2 ≤ x 2 + 2 < 3 2 3 < 2 x 2 + 2 ≤ 1 ⇒ - 2 3 > - 2 2 + x 2 ≥ - 1 ⇒ 1 3 > 1 + - 2 2 + x 2 ≥ 0 Hence, the range of f x is 0 , 1 3