The great circle distance from LAT 38°17'N, LONG 123°16'W to LAT 35°01'N, LONG 142°21'E is 4330 miles, and the initial course is 300.9°T. Determine the latitude of the vertex.
Official USCG Answer & Rule Citation
Correct Answer: Option C — 47°40.5'N
The vertex of a great circle is the point of highest latitude. Using the spherical trigonometry formula sin(Lat_v) = cos(Lat_1) * sin(Initial_Course), where the initial course is 300.9°T, the latitude of the vertex is calculated to be 47°40.5'N, representing the apex of the shortest distance arc.
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