Question
Question: Domain of f(x) = sin<sup>−1</sup>\(\left( \frac{\lbrack x\rbrack}{\{ x\}} \right)\), where [.] and {...
Domain of f(x) = sin−1({x}[x]), where [.] and {.} denote the greatest integer function and fractional part respectively, is
A
(0, 1)
B
(-1, 1) ~ {0}
C
(-2, 2) ~ {-1, 0, 1}
D
None of these
Answer
(0, 1)
Explanation
Solution
We must have, −1 ≤ {x}[x] ≤ 1
From −1 ≤ {x}[x], we get {x}{x}+[x] ≥ 0
⇒ {x}x > 0 ⇒ x ∈ (0, ∞) ~ I+ .
From, {x}[x] ≤ 1 we get, {x}[x]−{x}≤ 0
⇒ [x] ≤ {0} ⇒ x ∈ (-∞, 0)∪(0, 1)~I+
Thus domain is (0, 1).