$\"\"$

The expression is $\"Syntax$ .

Let $\"\"$ .

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

$\"\"$

Definition of $\"Syntax$ .

$\"\"$

Trigonometric even identity function $\"italic$ .

\ \

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

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

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

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

$\"\"$

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