Concept:The greatest integer function
[x] is constant between consecutive integers, so the two one-sided limits at
x=3 must be checked separately.
Explanation:For
x→3−,
x takes values just less than 3, such as 2.9, 2.99, 2.999.
Hence,
[x]=2.
Substituting this value,
x−3[x]−3=x−32−3=x−3−1Here,
x−3 is a very small negative number, so
x−3−1→+∞.
Therefore,
x→3−limx−3[x]−3=+∞For
x→3+,
x takes values just greater than 3, such as 3.1, 3.01, 3.001.
Hence,
[x]=3.
Substituting this value,
x−3[x]−3=x−33−3=0Therefore,
x→3+limx−3[x]−3=0Since the left-hand limit and the right-hand limit are not equal, the two-sided limit does not exist.
Answer:The limit does not exist.
Correct option: D.