The genral from of the .
Observe the graph :
\The distance from the maximum to the minimum value of the function is
Half of the distance from the maximum to the minimum value of the function is
So the amplitude is .
Period
Here the function completes one period on .
Substitute Period in Period formula
.
The midline appears at , there is no vertical shift .
Since the midline appears at , the value of
.
Since there is no phase shift, the value of .
Substitute ,
,
and
.
The equation correspond to the graph is .
Therefore the answer is .
Therefore the answer is .