Prove that lim gn for n→∞ exists, and find it.

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SUMMARY

The discussion centers on proving the existence of the limit of the sequence \( g_n \) as \( n \) approaches infinity, under the conditions \( 0 < g_n < 1 \) and \( (1 - g_n)g_{n+1} > \frac{1}{4} \) for all \( n \). The key insight is to demonstrate that the sequence \( g_n \) is increasing by establishing the inequality \( \frac{1}{4(1-x)} \geq x \) within the relevant interval. This leads to the conclusion that the limit exists and can be determined through further analysis of the sequence's behavior.

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Suppose g1 , g2 ,... are any numbers that satisfy the inequalities
0 < gn < 1 and (1 − gn )gn+1 > 1/4 for all n.

Prove that lim gn for n→∞ exists, and find it.


I need well substantiated answer! Thanks.
 
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dannysaf said:
Suppose g1 , g2 ,... are any numbers that satisfy the inequalities
0 < gn < 1 and (1 − gn )gn+1 > 1/4 for all n.

Prove that lim gn for n→∞ exists, and find it.


I need well substantiated answer! Thanks.


Is this a homework problem? I'll give you a hint. Show:

\frac 1 {4(1-x)} \ge x

on the interval, consequently showing your sequence gn is increasing. Then...
 

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