Homework for ECS 122A

Homework is due at 5pm on the due date in the Homework Box in 2131 Kemper Hall. The problems assigned in the book are the same in both the second and third edition. Problems with a decimal point in the number are at the end of sections in the book, those without a decimal point are at the end of a chapter.

Advice on mathematical writing, from a course at Purdue (thanks to Prof. Rogaway for pointing this out!). You may hand in one, and only one, homework assignment, up to 10 days late.

Our decisions on how much partial credit is given on homework are final. So do your best to present the solutions you have as nicely as possible; you will not get credit for something that was not clear from the homework paper itself.

Incorrect solutions might get partial credit, but a student who recognizes that the solution is incorrect is doing better than a student who has the same solution but believes that it is correct. So we will give roughly 1/4 credit for writing "I don't know", and then possibly more partial credit for any partial solutions, insights into the problem, etc, which you can give.

Often the answer to a problem is not obvious, even to a graduate student, a professional, or a professor. There may be some problems you cannot solve.

I recommend that you try to solve all the problems on your own first, without help from friends, without using the Web, without checking other books, etc. Often there are many possible approaches that seem reasonable. By trying some approaches that don't work, you learn why they don't work. This helps you solve other problems later, recognize easy special cases when they arise, etc. If you immediately get the solution from somewhere else, even if you do learn that solution really well, you miss this experience.

I also recommend working on the problems in a group. It helps keep you motivated, and brainstorming together can be very productive. Even when you none of you know the answer, you can talk about what to try, what you can figure out, and so on.

While you are welcome to use books, the Web, or your friends for help with the homework, your solutions must be written up clearly in your own words. This means you should be alone, and not looking at any online or hardcopy reference materials. If you can write the solution under these conditions you can be sure you understand it, and you will be able to use your understanding on an exam.

Try to write your solutions clearly and succinctly. Use complete sentences. Poorly written solutions correct solutions will not recieve full credit.

Like writing an English paper, it is helpful to write a first draft and then revise it. Typeset solutions are welcome; an acceptable compromise is to type the text, print it out, and then write in equations and pictures by hand. If you do write the text by hand please make a real effort to write neatly. We may mark down papers which are difficult to read (tiny writing, illegible writing, poor attempts to type equations in ACSII, etc.).

But don't get so hung up on writing a perfect solution or getting the correct result that you instead hand in nothing! We want to know that you are working on the problems and we want to give you credit for it!