Bill Goodwine's Courses

Posted: **Thu Oct 24, 2013 11:12 am**

Reading: all of chapter 5.

Exercises: 5.2 (parts 1-4, skip part 5), 5.5, 5.7, 5.9, 5.12 and 5.13 (part 1 only of 5.13)

Posted: **Fri Oct 25, 2013 1:00 pm**

For problem 5.2 part 2, is it supposed to say t=0 instead of x=0? And for part 5, is that worded right? If so, when did we change a 6 to a 5?

Posted: **Fri Oct 25, 2013 1:21 pm**

bgerig1 wrote:For problem 5.2 part 2, is it supposed to say t=0 instead of x=0? And for part 5, is that worded right? If so, when did we change a 6 to a 5?

Part 5 refers to problem 5.1. Since that wasn't assigned, you don't have to do it. I'll modify the homework to reflect this.

For the first part, see here: http://controls.ame.nd.edu/mediawiki/in ... #Chapter_5

Posted: **Mon Oct 28, 2013 6:22 pm**

Question 5.7 says that we are finding the solution to Airy's equation, but the equation listed is different from Airy's equation earlier in the book. The question has +xy, while section 5.5.1 has -xy. Should these be the same or are they correct as written?

Posted: **Mon Oct 28, 2013 7:26 pm**

sbrill wrote:Question 5.7 says that we are finding the solution to Airy's equation, but the equation listed is different from Airy's equation earlier in the book. The question has +xy, while section 5.5.1 has -xy. Should these be the same or are they correct as written?

Do it as written. All those "famous" equations can have different signs, etc.

Posted: **Tue Oct 29, 2013 6:11 am**

I have completed almost all the homework due Wednesday, but I am having a lot of trouble plotting my series solutions for the problems that require a plot. If you could explain to me or provide an example of how to plot a series solution in MATLAB that would be very appreciated. Thank you very much!

Look here: viewtopic.php?f=229&t=456

Posted: **Tue Oct 29, 2013 11:41 am**

For problem 5.12, when I plot my numerical solution the solution changes when I changed my range of t. Do you have to avoid the singularity points when finding the numerical solution?

Posted: **Tue Oct 29, 2013 12:15 pm**

jbruns2 wrote:For problem 5.12, when I plot my numerical solution the solution changes when I changed my range of t. Do you have to avoid the singularity points when finding the numerical solution?

Don't run ode45 past t=1. It probably can't handle the singularity through that. (I'm guessing this is the issue).

Bill Goodwine's Courses

Homework 6, due October 30, 2013

Homework 6, due October 30, 2013

Re: Homework 6, due October 30, 2013

Re: Homework 6, due October 30, 2013

Re: Homework 6, due October 30, 2013

Re: Homework 6, due October 30, 2013

Re: Homework 6, due October 30, 2013

Re: Homework 6, due October 30, 2013

Re: Homework 6, due October 30, 2013