Step 1:

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(1)

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The expression is $\"\"$ . \ \

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$\"\"$ \ \

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$\"\"$ .

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Step 2: \ \

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(2)

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The expression is $\"\"$ .

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The cosine function range between $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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According to squeeze theorem , if $\"\"$ for all $\"\"$ in an open interval containing c , except possibly at c itself, and if $\"\"$ ,then $\"\"$ exists and is equal to $\"\"$ .

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So now we have to find $\"\"$ and $\"\"$ .

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Given $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .

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Hence, $\"\"$ .

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Solution:

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(1) $\"\"$ . \ \

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(2) $\"\"$ .