1. The problem statement, all variables and given/known data Hello: An airplane is flying near a radar tower. At the instant it is exactly 3 miles due west of the tower. It is 4 miles high and flying with a ground speed of 450 mph and climbing at rate of 5 mph. If at the instant it is flying east, what is the rate of approach to the tower. So I think this means that its position is [-3 0 4] if we take the tower to be located at [0 0 0] and its velocity is [450 0 5]. I thought that the derivative of the position function evaluated at [-3 0 4] and multiplied by the velocity vector will give us the rate of approach. But would the position function be [450t 0 5t]? This looks wrong. Thanks!