Position of the horse after seconds can be modeled by
.
Where
\ : time in seconds.
: phase shift.
Compare the above equation with .
Here and
.
Period
Period is .
Here period is the function reaches a maximum height at
radians.
Phase shift is the difference between the horizontal positions of the function at and
.
Therefore phase shift is .
Phase shift .
Substitute in
.
Thus, the equation is .
The equation is .