Functions of the same famil have the same... (?) Can someone help with the answer??

It depends upon how you define a family of functions.

I think it is looking for a vocab word but not sure What do you think

Yes, I can help you with that! Functions of the same family have the same characteristics or properties. In order to determine what specific characteristic is being referred to in this question, we need more context or information. Could you please provide additional details or clarify your question?