$\"\"$

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The limit of the function is $\"\"$ .

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The squeeze theorem :

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If $\"\"$ when $\"\"$ is near to $\"\"$ $\"\"$ then $\"\"$ .

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Use the squeeze theorem, so find the function $\"\"$ smaller than $\"\"$ and a function $\"\"$ greater than $\"\"$ ,

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such that $\"\"$ and $\"\"$ are approaches to $\"\"$ .

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The range of sine function is $\"\"$ .

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So $\"\"$ .

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Multiply with $\"\"$ throughout the equation.

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$\"\"$

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By the squeeze theorem $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$ , then $\"\"$ .

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Therefore $\"\"$ .

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Graph :

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Graph the functions on the same plane.

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(1) Draw the coordinate plane.

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(2) Graph the function $\"\"$ .

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(3) Graph the function $\"\"$ .

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(4) Graph the function $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .