When you are asking a question about the speaker purpose and audience of text you are analyzing?

The rhetorical situation

Explanation:

The rhetorical situation is the set of circumstances that surrounds an event. This consists of an issue, an audience and a set of constraints. In this case, the event would be the text. By analyzing the purpose of the speaker we are analyzing the issue. On the other hand, by analyzing who is going to read the text, we are analyzing the audience. Both of these factors allow us to understand the rhetorical situation of a text.

When asking about the purpose of a speaker and the audience of atext, you're asking what the purpose of the speech is.