Final answer:
The purpose of an author in every book can vary, but they may aim to convince, entertain, consider, or train readers.
Step-by-step explanation:
The purpose of an author in every book can vary, but some common goals include convincing, entertaining, considering, and training readers. Authors may aim to convince readers of a particular idea or viewpoint, entertain them with an engaging story or captivating characters, consider their perspectives and emotions, or train them in a certain skill or knowledge. For example, persuasive essays and non-fiction books are often written with the goal of convincing readers, while novels and stories are crafted to entertain and engage. Overall, the purpose of an author can depend on the genre, style, and content of the book