<PRE><B>Question 433273</B>
Assuming northeast is 045 degrees:
Use the Cosine Law.
a = 80 miles, b = 60 miles and the included angle = 45 degs
d^2 = 80^2 + 60^2 - 2*80*60*cos(45)
d^2 = 10000 - 9600*sqrt(2)/2
d^2 =~ 3211.77
d =~56.67 miles
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The distance between them at any time t, t in hours, is
{{{d = sqrt(2500t^2 - 4800*sqrt(2))}}} miles
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