Question

A plane flying with a constant speed of 24 km/min passes over a ground radar station at an altitude of 6 km and climbs at an angle of 20 degrees. At what rate, in km/min is the distance from the plane to the radar station increasing 3 minutes later?

Answer 1

using Law of Cosines you can find distance "d"
\[d = \sqrt{36+576t^{2}-288t \cos(110)}\]
take derivative to get rate, then plug in t = 3