$\"\"$

\

The expression is $\"\"$ .

\

To find the value of $\"\"$ .

\

$\"\"$ (Apply Pythagorean identity)

\

$\"\"$ (Substitute $\"\"$ )

\

$\"\"$

\

$\"\"$

\

$\"\"$ (Take the square root of each side)

\

$\"\"$

\

$\"\"$ is in the first quadrant, cos $\"\"$ is positive, $\"\"$ . $\"\"$

\

Now find the $\"\"$ .

\

$\"\"$ (Apply double-angle formula)

\

$\"\"$ (Substitute $\"\"$ and $\"\"$ )

\

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

\

$\"\"$ (Apply double-angle formula)

\

$\"\"$ (Substitute $\"\"$ )

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ (Apply half-angle formula)

\

$\"\"$ (Substitute $\"\"$ )

\

$\"\"$

\

$\"\"$

\

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

\

$\"\"$ (Apply half-angle formula)

\

$\"\"$ (Substitute $\"\"$ )

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

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

\

The values of $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ .