Math 2200 Homework 5 Due Date: February 25

Math 2200 Homework 5
Due Date: February 25
The material in Chapter 4 is newer and more difficult than Chapters 1-3. Before you attempt the proofs,
study the given examples, try to make up your own examples, and make sure you have a solid understanding
of the definitions! Read and understand the proofs in the notes, then test yourself by trying to reconstruct
the proofs yourself.
As usual, the assigned exercises ask you to prove and/or disprove various claims. Work on all the other
exercises too! For computational exercises like 4.1.12, try them and then check your solution. A good way to
check computations is using Wolfram Alpha. Go to and type in what you want to
solve. For instance, type “factor 909090” and Wolfram will do so! Or type “gcd(15,25)” or “lcm(100,100)”.
Since Wolfram is pretty smart, you don’t have to worry too much about the exact syntax you use.
Submit your solutions in class on Monday or by 5 PM in my office.
Exercises to be Submitted
4.1.5, 4.1.16
Not to be Submitted
4.1.12, 4.1.14, 4.1.15, 4.2.4, 4.2.8