\"\" \ \

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The series is \"\". \ \

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Ratio Test : \ \

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(i) If \"\", then the series is \"\" is absolutely convergent. \ \

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(ii) If \"\" or \"\", then the series is \"\" is divergent. \ \

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(iii) If \"\", then the ratio test is inconclusive. \ \

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Here \"\" and \"\". \ \

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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, the series \"\" is converges by using ratio test.\"\" \ \

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The series \"\" is converges by using ratio test.