Math 221/821

Ordinary Differential Equations

Math 221: Differential Equations
Texas A&M University, Summer 2014
  • Syllabus for 8:30 class
    Syllabus for 10:30 class
  • Homework Problems Homework on 3.6: 1, 3, 7, 9, 23, 24
    Unlesss otherwise stated in class, homework is due at the beginning of class the second lecture day after when it was assigned, for example, if we have lecture on M,W,F, the material discussed on Monday will be due on Friday, and the material discussed on Wednesday will be due the following Monday, unless Monday is a holiday, in which case it would be due the following Wednesday.
    This means you should read the section we are going to discuss before coming to class.
  • Contacting me: The best way to contact me is via email. Please note that you should not expect an immediate response 24 hours a day, but that I will try to answer your email in a reasonable amount of time (usually I am pretty fast). When emailing, be sure to include your full name, course and section.
    Here's what I'd like to see in email.
  • Exam Keys:
    Exam 1 Key
    Exam 2 Key
    Exam 3 Key Typo on question 1: Solution should be x(t) = 2e^(2t)(1,3) - 2e^(4t)(1,1)
  • Online Phase Portrait Plotting

  • Computer Resources

    "Think twice, code once." -Anonymous

  • MATLAB help:
  • Remote Login:
    • If you have a Linux or Mac machine, the easiest way is just to open a terminal and enter:
      ssh -X matlab
      Make sure to replace YOUR_CALCLAB_USERNAME with the user name you use to login in class.
    • NoMachineNX and VOAL Tutorials. Use this for remote login for Linux/Mac/Windows machines.
  • Linux:
  • Study Tips

    Tips you can use to increase your academic effectiveness.

    Being able to study efficiently is a skill that takes time to develop. It is normal to discover that the study habits and skills that worked for you in highschool or as a freshman need to be updated and improved if you are going to keep from being overwhelmed. It takes time and effort, as well as trial and error, to find which study habits work best for you. Below are some suggestions and resources to get you started. Good luck, and study efficiently!
  • Build a solid foundation, if you haven't already.
    1. A solid foundation in calculus is required for this course, especially knowledge of integration and integrals.
    2. Integration help
    3. Many people do not realize that they still have some issues with algebra. Success in this course will be almost impossible if there are too many holes in your algebraic skills, especially those concerning logs and exponents. Fix any issues as soon as possible so that you will be able to do your best.
    4. Here's one Exponent and Log review. Use Google to find more.
  • Tips on doing homework
    1. On the same day the homework is assigned, read over all the problems. This will get you thinking about them early on. The problems will stay in your brain on the "back burner", and you may have more luck later when you sit down to work them.
    2. Do all the homework problems, even if you don't get them in on time.
    3. Homework is excercise. If you want to get better at sports, you need to excercise everyday. If you want to get better at mathematics, you need to work on problems every day.
  • Advice from students for doing better on exams
    1. Study with more people. Study in groups or with a partner. Work problems together on a white board. Take turns challenging each other. Being able to explain a problem clearly to someone else is a major step towards understanding it.
    2. Pay attention in class and to the instructor's emails.
    3. Rework what you didn't understand well.
    4. Write down short examples on the notecard.
      Note: Notecards are not allowed on exams; the pupose of this tip is to help with studying.
    5. Label formulas on your cards.
    6. Theorems should be on the notecard.
    7. Keep a running list of things for your notecard rather than trying to compile it all at the last minute.
    8. Write down formulas completely and correctly.
  • Advice on how to predict what is on the exam (in addition to some of the above):
    1. Old exams are a hint.
    2. Pay attention to problems done in class several times.
    3. Take note of quiz questions; one of those might become an exam question.
    4. Problems tend to be similar to homework/suggested homework.
  • In Class
    • Make sure you have read the section we are covering before you come to class.
    • Please be assertive in asking questions during lecture.
    • Please be assertive in paying attention in lecture.
    • Remember that you are responsible for all material presented in lecture, no matter how strongly you felt it was emphasized.
  • Links* to articles on efficient study habits
    1. Case Study: Why the Number of Hours You Spend Studying Means Nothing

    2. Case Study: How I Got the Highest Grade in my Discrete Math Class

    3. Case Study: How Tyler Aced a Difficult Course

    4. Case Study: How Amy Saved Her College Career

    5. Finals Diaries: Travis Prepares to Battle Calculus

    6. The Grade Whisperer: Eric Prepares to Battle English Lit

    7. How Ricardo Aced Computer Science Using His iPhone (An alternative would be to use Anki.)

    Study Hacks "Four Weeks to a 4.0" series

    1. Week 1

    2. Week 2

    3. Week 3

    4. Week 4

  • Some of the above material is taken from Jean-Marie Linhart's site, which has some great resources. See her excellent website on Success at Math.

  • * Use the external links on this page only according to your own judgement; I am not responsable for, nor in control of, their content. The opinions given there do not necessarily reflect my own, and I do not officialy endorse any statements made on the websites which are linked to, nor any of the content linked to therein.