Hi Jeffrey,
In a real airplane you need to consider the location of the starting airport and other factors like wind and magnetic declination.
If you are just asking how to do a trigonometry problem in Wolfram syntax and convert from degrees to radians and whatnot, you can use a function like this:
bearing[b1_, d1_, b2_, d2_] :=
180/Pi Mod[
ArcTan @@
N[d2 {Cos[b2 Degree], Sin[b2 Degree]} -
d1 {Cos[b1 Degree], Sin[b1 Degree]}], 2 Pi]
bearing[63, 1000, 153, 800]
204.34
That is the true bearing. To get the relative bearing just subtract the heading of the first plane.
