Final answer:
To use passing or diverging separation courses, they must diverge by at least 15 degrees.
Step-by-step explanation:
In order to use passing or diverging separation courses, the courses must diverge by at least 15 degrees. This means that the courses must move away from each other at an angle of 15 degrees or more. If the courses diverge by a smaller angle, they would still be considered converging rather than passing or diverging.