Analysis Proof: prove that sqrt(x_n) also tends to 0

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SUMMARY

The discussion centers on proving that if the sequence \( x_n \) approaches 0 as \( n \) approaches infinity, then \( \sqrt{x_n} \) also approaches 0. The proof presented utilizes the epsilon (\( \epsilon \)) definition of limits, establishing that for any \( \epsilon > 0 \), there exists a natural number \( N \) such that for all \( n > N \), \( |x_n| < \epsilon \) implies \( |\sqrt{x_n}| < \epsilon \). A concern is raised regarding the case when \( x_n < 1 \), specifically questioning the validity of the proof under this condition.

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  • Understanding of limits in calculus
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  • Basic knowledge of sequences and their convergence
  • Proficiency in manipulating inequalities
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  • Study the epsilon-delta definition of limits in detail
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  • Investigate the implications of bounding sequences, particularly for \( x_n < 1 \)
  • Learn about the properties of continuous functions, specifically the square root function
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Homework Statement


Suppose sequence x_n tends to 0 as n approaches infinity, prove that sqrt(x_n) also tends to 0
x_n is a sequence of non negative real numbers

Homework Equations

The Attempt at a Solution


Proof. Let e>0. There exists an N in the naturals such that for n>N Ix_nI < e So if I choose an N such that x_n < e whenever n>N then Isqrt(x_n)I<x_n<e

e is epsilon.

Is this proof correct?
 
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Mathematicsresear said:

Homework Statement


Suppose sequence x_n tends to 0 as n approaches infinity, prove that sqrt(x_n) also tends to 0
x_n is a sequence of non negative real numbers

Homework Equations

The Attempt at a Solution


Proof. Let e>0. There exists an N in the naturals such that for n>N Ix_nI < e So if I choose an N such that x_n < e whenever n>N then Isqrt(x_n)I<x_n<e

e is epsilon.

Is this proof correct?
What if ##x_n < 1\,?## E.g. ##\sqrt{\frac{1}{100}} = \frac{1}{10} > \frac{1}{100}##.
 

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