Final answer:
Monotone sequences can have a well-defined limit because they are always bounded, either increasing or decreasing, and are convergent.
Step-by-step explanation:
We know that lim sn is always meaningful for monotone sequences because:
- Monotone sequences are always bounded, ensuring a well-defined limit. This means that the sequence does not go to infinity or negative infinity.
- Monotone sequences are always either increasing or decreasing, allowing for the existence of limits. This means that the sequence is moving towards a specific value.
- Monotone sequences are always convergent because they are either always increasing and bounded above or always decreasing and bounded below. This guarantees that the sequence will approach a specific value.