\"\"

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Prove that cosine is a continuous function.

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To prove that sine is a continuous function, prove \"\".

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Theorem : \"\" is continuous at \"\" if and only if \"\".

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Now prove \"\".

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Consider the limit \"\".

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\"\"

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Properties of limits: \"\" and \"\".

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                             \"\"

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\"\".

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Therefore, \"\".

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Cosine is a continuous function.

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\"\"

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Cosine is a continuous function.