$\"\"$

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The series is $\"\"$ .

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Limit comparison test :

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Suppose that $\"\"$ , $\"\"$ , and $\"\"$ , where $\"\"$ is finite and positive.

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Then the two series eithe converge or both diverge.

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Consider the series $\"\"$ and $\"\"$ .

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Find $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .

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Therefore, $\"\"$ and $\"\"$ either both converge or both diverge.

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$\"\"$

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The series is $\"\"$ .

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The series is in the form of $\"\"$ -series.

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The $\"\"$ -series $\"\"$ is divergent if and only if $\"\"$ .

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Here $\"\"$ .

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The series $\"\"$ is divergent.

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Therefore, the series $\"\"$ is divergent.

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$\"\"$

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The series $\"\"$ is divergent.