The expression is .
To find the value of .
(Apply Pythagorean identity)
(Substitute
)
(Take the square root of each side)
is in the fourth quadrant, sin
is negative,
.
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
.