Question
Question: Domain of f(x) = \(\sqrt{2\{ x\}^{2} - 3\{ x\} + 1}\)where {.} denotes the fractional part, in [-1, ...
Domain of f(x) = 2{x}2−3{x}+1where {.} denotes the fractional part, in [-1, 1], is
A
[−1,1]∼(21,1)
B
[−1,−21]∪[0,21]∪{1}
C
[−1,21]
D
[−21,1]
Answer
[−1,−21]∪[0,21]∪{1}
Explanation
Solution
We must have
2{x}2 − 3{x} + 1 ≥ 0 ⇒ {x} ≥ 1 or {x} ≤ 1/2
Thus we have 0 <{x} ≤ 1/2
⇒ x ∈ [n,n+21] , n ∈ I.