a vehicle , say A, starts 13km north of an intersection and proceeds due south at 50kph. Another vehicle, say B, starts 8km east of the intersection and proceeds due west at 40kph.

A) find equasions for the y coordinate of the first vheicle and the x coordinate of the second vehicle

B)find an expression for the square of the distance between the two vehicles. differentiate both sides

C) solve for ds/dt=0 and show minimum distance occurs at just under 15 mins fromt=0

D) find distance at this time

e)find the rate of approach at time t=.1hours

what do i need to do?