$\"\"$

Complete the table:

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$
$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$

Observe the results in the above table, the values of $\"\"$ tends to $\"\"$ as $\"\"$ tends to $\"\"$ .

Therefore, $\"\"$

$\"\"$

$\"\"$ .