Question

explain the three main techniques of persuasion?

Answer 1

I can think of many techniques for persuasion.

What does your text list as these techniques?

Answer 2

Ethos - Authority
Pathos - Emotion
Logos - Logic

Answer 3

Authority tells you to do it -- or else!

Emotion appeals to your sympathy or guilt.

Logic tries to persuade you with rational arguments.

Answer 4

If you saw the Godfather I movie, you saw all three used in offers that could not be refused.

Answer 5

Although they are not defined in your terms, here are some articles on factors in persuasion. They are more specific examples of your three techniques.

http://www.members.cox.net/dagershaw/lol/InfluenceAntecedents.html
http://www.members.cox.net/dagershaw/lol/InfluenceMorePrinciples.html
http://www.members.cox.net/dagershaw/lol/InfluenceStillMore.html

I hope this helps a little more. Thanks for asking.