$\"\"$

\

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

\

The squeeze theorem :

\

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

\

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

\

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

\

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

\

So $\"\"$ .

\

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

\

$\"\"$

\

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

\

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

\

Therefore $\"\"$ .

\

$\"\"$

\

$\"\"$ .