(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
.