The trigonometric expression is $\"\"$ .

Let $\"\"$ .

Take the angle $\"\"$ in the interval $\"\"$ .

$\"\"$

Definition of $\"\"$ .

$\"\"$ .

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

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

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

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

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