What is the purpose of an index in an informative text?

Answer:This is used to give a reader an informative and useful guide about the text, it identifies important vocabulary words and their definitions, it also shows the reader where to find an information in the text

Answer: The purpose of the index is to give the reader an informative, balanced portrait of what is in the book and a concise, useful guide to all pertinent facts in the book. These facts, in the form of an alphabetically ordered list of main entries and subentries, will include both proper names and subjects.