i need help on comparative analysis of waterfall,prototype and agile methodologies.give me some instructions how should i do it.i have to write a 3000 words essay on this topic.what points should i keep in mind while writing it
How about you need to read books? You are taught in class or have text books for that. The assignment is to make you think and understand each technique of software development life cycle. I am sorry, I can't give you an easy way out because you won't learn anything by copying other people's opinion and understanding about them.
Hmm... You don't have text book describing these methods? You could also use any online article if you want. Search for software life cycle and software engineering. They all should be included in software engineering class.
When you read, look for any unique features/characteristics of the method. How you would do it. They all are different. Also, look for advantages and disadvantages. However, certain advantages may not be true under certain circumstances. You may need to think about it. If you can't think of one, don't worry about it. You may not know because you may not have experiences in real life. But you will understand when you encounter one.