If we have a real sequence |an| such that limn→∞an=a, how do we prove (by an ϵ−N argument) that |an| such that limn→∞a2n=a2?
I know you can use algebra to do to the following:
|a2n−a2|=|(an−a)(an+a)|
Where I feel like you can use the implication that limn→∞an=a to show that (an−a)<a or something.
What's the proper way to go about this?
Answer
Hint
A convergent sequence is bounded. So you can also bound |a+an|.
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