Let , x1∈(0,1) be a real number. For n>1 define xn+1=xn−xn+1n. Then prove that limn→∞xn exists.
We have to prove that the given sequence {xn} is convergent. So we have to show that {xn} is monotone and bounded.
I proved that the sequence is monotone decreasing. But I'm unable to show that it is bounded below. How can I show it ?
Any other way to prove that the limit exists ?
Answer
We show by induction that xn∈(0,1) for all n:
The case n=1 is clear.
Now let n∈N and xn∈(0,1)
Then: xn+1=xn(1−xnn). From xn∈(0,1) we get xnn∈(0,1) and therefore 1−xnn∈(0,1).
Consequence: xn+1∈(0,1).
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