The distance of police care from the intersection is independent of the distance of the suspect from the intersection.
The distance of police car from the suspect car depends on the the distance of each from the intersection.
When [math]x=8[/math], the distance between police car and suspect car is
When [math]x=5[/math], the distance between police car and suspect car is
The minimum distance between the police car and the suspect car happens when [math]\frac{dD}{dt}[/math] is