Thank you!
It depends, english-learner. What is your context? Maths, economics, something else? In each case it can be explained differently. Basically it is a dependencyE.g., cause-and-effect realtionship.
Here is the sentence:
Form functional relationship with responsible adult.
Oh, then I suppose it's just cooperation that's implied here - "functional" means interaction when solving some problems, that is when "functions" of one participant add those of the other one and then start working together... This is what I can understand from your sentence.
Hope my explanations are not too confusing![]()