\
The values are
and
.
The angle
is lies in first quadrant.
The value of cosine function is
.
The angle
is lies in fourth quadrant.
The point
is lies on the curve of radius
.
Thus,
\

The value of sine function is
.
\
(a)
\The expression is 
Sum formula for the sine function:
.
Substitute
and
in above equation.

Thus,
.
\
(b)
\The expression is
.
Sum formula for the cosine function:
.
Substitute
and
in above equation.

Thus,
\
.
\
(c)
\The expression is
.
Subtraction formula for the sine function: 
Substitute
and
in above equation.






Thus,
.
\
(d)
\The expression is
.

Subtraction formula for the cosine function: 


From (c),
.

.
(a).
.
(b).
.
(c).
.
(d).
.