Question

A handbook teaching people how to negotiate

is it to inform, persuade, or entertain

And how do you know? write a sentence explaining your answer

Answer 1

The purpose would be to inform.

If the purpose of the authors writing is the persuade, it would look more like: Why You Should Negotiate With Others

If the purpose was the entertain, it could look something like: John Doe and the Negotiating Lizard

Since it’s a handbook teaching you how to do something, it is informing you on how to perform a certain task and how to do it properly.

So the answer is to inform.