MHB Determining convergence/divergence

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To determine convergence or divergence of sequences, evaluate the limit as n approaches infinity; if the limit exists and is a real number, the sequence converges. For sequences that may oscillate, particularly those involving powers of -1, be cautious as they may diverge. The Raabe test is recommended for series with positive terms as an efficient method for determining convergence. Utilizing a calculator can assist in evaluating limits for large n, but understanding the underlying principles is crucial. Mastering these techniques can help efficiently tackle test questions on convergence and divergence.
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what's the easiest way to quickly determine convergence or divergence? or is there a way to do it by calculator? i have a test today and most of the questions ill be given a series (few sequences) and itll be asking whether they converge or diverge?
 
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If you can show that:

$$\lim_{n\to\infty}a_n=L$$

where $L\in\mathbb{R}$, then the sequence converges. If you doubt the outcome of your limit, then you could evaluate $a_n$ for large values of $n$ as a means to try to verify your result. Just be mindful that if $a_n$ contains a power of $-1$, then the sequence could oscillate between two limiting values and is thus divergent.
 
ineedhelpnow said:
what's the easiest way to quickly determine convergence or divergence? or is there a way to do it by calculator? i have a test today and most of the questions ill be given a series (few sequences) and itll be asking whether they converge or diverge?

What do you mean by 'easy' or 'quickly'? ... in Your place I would look for the most efficient test to determine if a series converges or diverges ... for the series with positive terms the more efficient test in my opinion is the Raabe test...

Kind regards

$\chi$ $\sigma$
 
@chisigma i mean the simplest method that can help me get through the problems quickly
 
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