$\"\"$

The expression is $\"\"$ .

Let $\"Syntax$ , take the angle $\"\"$ in the interval $\"\"$ .

$\"\"$ (Since $\"\"$ ) \ \

Definition of $\"\"$ .

$\"\"$

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

$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$	$\"\"$
$\"\"$	$\"\"$	$\"minus$	$\"minus$	$\"minus$	$\"\"$	$\"1$	$\"\"$	$\"\"$	$\"\"$

Observe the table, $\"\"$ possible if $\"\"$ .

Therefore, the value of $\"\"$ is $\"\"$ .

$\"\"$

The value of $\"\"$ is $\"\"$ .