Answer:
The horizontal tangents occur at: (9,-2) and (11,2)
The vertical tangent occurs at (8.75,-1.375)
See attachment
Explanation:
The given parametric equations are:
and

The slope function is given by:


The tangent is vertical when



When
,
,

The vertical tangent occurs at (8.75,-1.375)
The tangent is horizontal when



When t=1,
,

When t=-1,
,

The horizontal tangents occur at: (9,-2) and (11,2)