The purpose of all topic sentence, depending on it's location, is to:

The purpose of all topic sentences is to announce what the paragraph will be about.  Besides all topic sentences have to be related to the thesis statement in order to achieve unity and focus in a text. A topic sentence generally appears in the first or second sentence in each body paragraph and serves to unify the content of the paragraph. Paragraph unity should be  accomplished if all the paragraph sentences are related to the topic sentence. When the paragraph contains restated ideas from the whole text, the topic sentence is placed at the end as a concluding statement.

it wants you to read whatever it gave you. then compare it to the others you read. you need to use textual evidence, and cite anything you do!

hope this !

~courtney

an argumentative essay presents objectively a topic and its main characteristics. besides, it states all this information and facts by giving authentic and substantiated proof to the audience. by contrast, a persuasive text purpose is to convince the audience about some facts by presenting them according to his/her emotions and feelings. the main purpose of a persuasive text is to convince the audience to agree with the author´s opinion. on the other hand, in the argumentative essay, the author leads the writer to recognize his/her point of view as the correct one.