NIMCET 2014 — Mathematics PYQ
NIMCET | Mathematics | 2014If f(x)={[x]sin[x],0,amp;[x]=0amp;[x]=0, where [x] is the largest integer but not larger than x, then limx→0f(x) is:
Choose the correct answer:
- A.
-1
- B.
0
- C.
1
- D.
Does not exist
(Correct Answer)
Does not exist
Explanation
Solution:
To find limx→0f(x), we must check the Left Hand Limit (LHL) and the Right Hand Limit (RHL) at x=0.
1. Right Hand Limit (RHL):
As x→0+, x lies in the interval [0,1).
For 0 \leq x < 1, the greatest integer function [x]=0.
According to the function definition, when [x]=0, f(x)=0.
2. Left Hand Limit (LHL):
As x→0−, x lies in the interval [−1,0).
For -1 \leq x < 0, the greatest integer function [x]=−1.
Since [x]=0, we use the first part of the function: f(x)=[x]sin[x].
Substituting [x]=−1:
Conclusion:
Since the Left Hand Limit and Right Hand Limit are not equal:
Therefore, limx→0f(x) does not exist.
Correct Option: 4
Explanation
Solution:
To find limx→0f(x), we must check the Left Hand Limit (LHL) and the Right Hand Limit (RHL) at x=0.
1. Right Hand Limit (RHL):
As x→0+, x lies in the interval [0,1).
For 0 \leq x < 1, the greatest integer function [x]=0.
According to the function definition, when [x]=0, f(x)=0.
2. Left Hand Limit (LHL):
As x→0−, x lies in the interval [−1,0).
For -1 \leq x < 0, the greatest integer function [x]=−1.
Since [x]=0, we use the first part of the function: f(x)=[x]sin[x].
Substituting [x]=−1:
Conclusion:
Since the Left Hand Limit and Right Hand Limit are not equal:
Therefore, limx→0f(x) does not exist.
Correct Option: 4