Answer:When someone presents a speech to either the public or private they aren't necessarily trying to inform others but they are trying to persuade or entertain their audeince to be interested in what they are saying. When you are doing a speech you sometimes have to prove your point in order for others to be on the same page as you.
Explanation: For presentations it can do all three inform, persuade, and entertain. For an informative presentation you are informing your audeince in on what you have been working and what are your goals for the specific thing that you want them to be aware of. Informative presentations serve to present specific information for specific audiences for specific goals or functions.
It all depends on what your presentation or speech is about. i hope this helps you out :)