A particle is moving through thexy

xy-plane in such a way that itsx

xcoordinate is changing at the rate of4

4m/s, and itsy

ycoordinate is changing at the rate of2

2m/s.

LetD

Dbe the distance between the particle and the fixed point(3,1)

(3,1).

How fast is the distanceD

Dchanging when the particle is at(2,0)

(2,0)?

Note thatD

Dis given by