Greg and Marshall are driving on a highway. At time t = 0, Greg begins travelling south at a speed of 50 km/h. A minute later, Marshall drives east at 40 km/h. At what rate is the distance between them increasing at t = 12 min?

Question

anonymous · Answer

The distance between them, in airway between their paths
will form a triangle
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anonymous · Answer

I got that although I'm not sure of the equation and the derivative of that

anonymous · Answer

A solution using Mathematica 8 Home Edition for the calculations is attached.