(a)
\The general form of cosine function is
.
where,
is amplitude,
is the period and
is the shift along
-axis.
Observe the graph. The difference between the maximum height and the minimum height is twice of the amplitude of the function.
\

.
The amplitude of the function is
.
Period of the function is
.
The cosine function completes one half of the cycle between the times at maximum height and minimum height.
\
.

\
.
Phase shift along
-axis is the time where maximum height occurs.
The time at maximum height is
.


Since midline
,hence 
Substitute
,
and
and
in
.

Therefore,the function is
.
(b)
\Rewrite the function
as a sine function.
The general form of sine function is
.
Observe the graph:
\The amplitude of the function is
and
.
The function has a phase shift of
units to left.
Therefore,
and
.
Substitute all the values in
.
Therefore,The function is
.
(c)
\Rewrite
as a cosine function of a single angle.
The function is
.
(d)
\The function is
.
Find all solutions of
.


The general solutions for
is
.
The solutions of
is
.
(e).
\The general function is
.
Where
is the phase shift around the
-axis.
observe the graph:
\There is no pahse shift around the
-axis.
Hence, the value of the
is
.
(a)The function is
.
(b) The function is
.
(c) The function is
.
(d) The solutions of
is
.
(e) There is no pahse shift around the
-axis.Hence, the value of the
is
.