Given:
altitude, x = 1 mile
speed, v = 560 mi/h
distance from the station, x = 4 mi
Solution:
To find the rate,

Now, from the right angle triangle in fig 1.
Applying pythagoras theorem:

differentiating the above eqn w.r.t 't' :
(1)
Now, putting values in eqn (1):




The rate at which distance from plane to station is increasing is:
