Try it on paper first. A hint, the key idea and the worked solution are here when you need them.
A counter shows the number for a sensor reading , where is the greatest integer not above . A technician watches the reading approach from below and from above. Find the limit of as tends to from the left. Then find the limit as tends to from the right. Finally find the value of at exactly . Remember that .
Squeeze: if and , then . Split at . For the greatest integer, is the largest integer not above , and .
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Given. .
Plan. Work out each bracket on each side of .
Step 1. From the left. For : and , so . Then .
Step 2. From the right. For : and , so . Then .
Step 3. At . .
Check. For a non-integer we always get . At an integer it is . So the limit is although the value is .
Answer: both one-sided limits are , so the limit is , and the value at is .
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