Homework 3, due September 19, 2007.

[goodwine]

Reading assignment: Chapter 1, section 1.8 and chapter 3.

Homework assignment: problems 3.1, 3.4, 3.8, 3.9, 3.11, 3.12 (if necessary, refer to the electronic pdf version of the course text for clearer graphs) and 3.14 from the course text.

In addition, write a computer program that uses Euler's method to determine an approximate numerical solution to the initial value problem in Problem 3.1. Submit a listing of your computer code as well as a plot of the solution. You may use FORTRAN, C, or C++, but not Matlab to determine the solution. You may use Matlab to plot the solution. If you would prefer to use an alternative programming language, you must receive permission from the instructor.

[scox7]

In section 3.4.2, page 74. Just under equation 3.16 there is u1(t) and u2(t), but there's no integral for u2(t). It's the same in the following equations for x particular and the final answer. There should be an integral there correct?

[goodwine]

In section 3.4.2, page 74. Just under equation 3.16 there is u1(t) and u2(t), but there's no integral for u2(t). It's the same in the following equations for x particular and the final answer. There should be an integral there correct?

Yes, you are correct.

[Luke Nakatsukasa]

is this the syntax for e^2

exp**2

[goodwine]

is this the syntax for e^2

exp**2

No, I think it should be

Code: Select all

exp(2)

[goodwine]

i thoght i should write in the do loop.. something along the lines of

x(1) = x(1) + x(2) dt
x(2) = x(2) + x(3) dt
x(3) = t**2 + 3*exp**t - 4*x(1) ! from problem 3.1

where am i going wrong?

A second order equation is equivalent to two first order equations, so there should only be an x(1) and x(2). If you do it the way I was last night, the derivative of x(1) is x(2) and the derivative of x(2) is determined from solving the original second order equation for d^2x/dt^2.

Also, if that's copied directly out of your code, you are missing an * for times in the first two equations.

[scox7]

For Problem 3.12, the graphs in both of the tables (Table 3.2, Table 3.3 p 80-81) do not have graphs plotted for "plot 2". What should we do as far as matching those graphs?

[goodwine]

For Problem 3.12, the graphs in both of the tables (Table 3.2, Table 3.3 p 80-81) do not have graphs plotted for "plot 2". What should we do as far as matching those graphs?

That's due to poor photocopying, I assume. Check the electronic version where you can zoom in/out as much as you want.

[lhaas]

page 64, the third equation in example 3.3.1:

there should be a 6 next to the last term

[scox7]

The electronic version looks the same. The line for "plot 2" in the legends appears to be white. Either way, the plots do not appear.

[goodwine]

The electronic version looks the same. The line for "plot 2" in the legends appears to be white. Either way, the plots do not appear.

They appear just fine in mine. I guess you need to ask someone, or if all else fails, stop by my office tomorrow morning.