Bill Goodwine's Courses

Posted: **Fri Sep 09, 2016 1:43 pm**

Reading: All of Chapter 2 and all of Chapter 3 except the variation of parameters section.

Exercises: 2.11, 2.13, 2.14, 2.15, 2.27, 2.29, 3.5, 3.7 and 3.11.

Posted: **Mon Sep 12, 2016 8:41 pm**

For problem 2.14, it says "use two methods to find the general solution for...", could one method be variation of parameters although you specified not to read that section in the textbook? Or is there another method (other than undetermined coefficients) that you are looking for?

Posted: **Mon Sep 12, 2016 8:42 pm**

nmejias wrote:For problem 2.14, it says "use two methods to find the general solution for...", could one method be variation of parameters although you specified not to read that section in the textbook? Or is there another method (other than undetermined coefficients) that you are looking for?

Variation of parameters is one of the methods available. It was part of the reading for Chapter 2, first order equations which this problem is, but not yet assigned for second order equations in chapter 3.

Posted: **Mon Sep 12, 2016 8:59 pm**

Someone asked me:

I have been working on Homework 3 and have a question regarding problem 2.14. The questions asks us to use two different methods to determine the general solution to the equations given and I used undetermined coefficients for the first method of solving and am planning to use variation of parameters for the second method (recognizing that need to use integration by parts multiple times). I was wondering if you would like us to do this integration by hand or use a computer program to solve?

For homeworks you can always use an integral table or Wolfram Alpha or something similar.

I do expect you to be able to integrate most elementary functions as well as recognize and use integration by parts. So a test is probably not the place to experience integration by parts for the first time in more than a year. Generally if there is a tricky integral I'll put an integral table on the back of the exam or just say to stop the problem when you get to the integral.

Posted: **Tue Sep 13, 2016 12:26 pm**

Should we include the graphs and/or solution for our verification of 3.11?

Posted: **Tue Sep 13, 2016 12:27 pm**

pkrog2 wrote:Should we include the graphs and/or solution for our verification of 3.11?

Yes (it says to do it at the end, after 7).

Bill Goodwine's Courses

Homework 3, due September 14, 2016.

Homework 3, due September 14, 2016.

Re: Homework 3, due September 14, 2016.

Re: Homework 3, due September 14, 2016.

Re: Homework 3, due September 14, 2016.

Re: Homework 3, due September 14, 2016.

Re: Homework 3, due September 14, 2016.