# Toronto Math Forum

## MAT244-2013S => MAT 244 Misc => Topic started by: Brian Bi on January 06, 2013, 05:43:03 PM

Title: Comparison of 9th and 10th textbook editions
Post by: Brian Bi on January 06, 2013, 05:43:03 PM
Hi all,

I'm looking for a volunteer---someone who has already bought the 10th edition of the textbook, or will do so shortly---who will meet me weekly, or bi-weekly, or however often problem sets are posted, so we can compare problem numbers between the 10th edition and the 9th edition (which I already have).

If I am able to get a volunteer, I will post corresponding problem numbers in this thread after each time we meet. This way, other students who already have the 9th edition, or can obtain it much more cheaply than the 10th, won't have to buy another edition of the textbook just so they can do the problems.

I'm sure people would give you karma for it  :P (which means bonus marks apparently)

Thanks!
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Victor Ivrii on January 06, 2013, 06:56:43 PM

I'm sure people would give you karma for it  :P (which means bonus marks apparently)

Thanks!

Well, commoners (people) cannot give karma in this forum as it translates to the bonus mark. I can--and will.   :D
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Yanyuan Jing on January 06, 2013, 09:13:30 PM
I wouldn't mind helping, though I haven't bought the book yet. Also, I don't think it'll need to be a weekly thing. I think all the assigned questions have already been posted, and there aren't any evaluated problem sets, just suggested practice problems.

I'll private message you to set up meeting times?

Yan
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Victor Ivrii on January 07, 2013, 01:09:07 AM
I wouldn't mind helping, though I haven't bought the book yet. Also, I don't think it'll need to be a weekly thing. I think all the assigned questions have already been posted, and there aren't any evaluated problem sets, just suggested practice problems.

I'll private message you to set up meeting times?

Yan

Some problems could be added (I will mark them by a special colour) so it is not one time thing but not every week either

Nice avatar!
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Victor Ivrii on January 07, 2013, 04:30:14 AM
Let me clarify this issue once and for all. Officially you use 10th edition. Neither 9th, nor 8th, etc.

Content however is only marginally different. Main issue here is home assignments. Usually publishers when preparing new edition shuffle problems like card sharpers to discourage of usage of the old edition because they want bigger sales. In this case there are some discrepancies, not very significant. Therefore using older edition you can add up with solving the wrong problem.

However you do not submit home assignments, they are not graded at all, but you are given quizzes drawn from the problems in the home assignments. So if you solved the right problem, you would solve during the quiz exactly same problem. If you solved the wrong problem, you would solve during the quiz similar problem, which makes a difference.

Yes, we posted online required problems for sections 1.1-2.2, but it was done only because textbook has not arrived to bookstore yet, so we were dealing with a problem of not our making. However it is time consuming. Creation of comparison table is also time consuming and error prone. So, you should not expect instructors to be involved in this. if there are volunteers--go ahead! (IMHO, if there are two independent pairs it would be more reliable).

PS. I have no idea how much the textbooks authors profit. AFAIK none of them is on the Forbes list.
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Brian Bi on January 07, 2013, 10:16:05 AM
I wouldn't mind helping, though I haven't bought the book yet. Also, I don't think it'll need to be a weekly thing. I think all the assigned questions have already been posted, and there aren't any evaluated problem sets, just suggested practice problems.

I'll private message you to set up meeting times?

Yan
Yes, do that.
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Jason Hamilton on January 11, 2013, 12:00:56 AM
I've noticed for almost all the questions so far, the 10th edition and the 9th edition are identical in the questions, no "shuffling" has taken place. However I only checked the assigned questions up to chapter 2.2
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Jihyun Bang on January 18, 2013, 11:27:09 AM
Can somebody check if the rest of chapter 2

(from 2.2 till the end) has the same questions between 9th and 10th edition ?

thanks for ur help
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Victor Ivrii on January 18, 2013, 11:44:15 AM
Can somebody check if the rest of chapter 2

(from 2.2 till the end) has the same questions between 9th and 10th edition ?

thanks for ur help

Why  anyone needs Chapter 2? You can download Ch 10th edition legally. And please, change Name to a proper one
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Brian Bi on January 22, 2013, 04:18:33 PM
Yanyuan and I compared problem numbers in chapters 1 through 4 today. We found that:
• Most questions and question numbers are identical.
• A few question numbers are different. Yanyuan will post these shortly.
• There are some minor stylistic differences, such as writing equations in the form $$M(x,y) + N(x,y)y' = 0$$ instead of $$M(x,y)\, dx + N(x,y)\, dy = 0$$
There is one problem whose text was actually changed between the two editions. In section 2.3, problem 12 in the 10th edition is similar to problem 11 in the 9th edition. The 9th edition reads:
Quote from: 9th edition
11. A recent college graduate borrows $100,000 at an interest rate of 9% to purchase a condominium. Anticipating steady salary increases, the buyer expects to make payments at a monthly rate of 800(1 + t/120), where t is the number of months since the loan was made. (a) Assuming that this payment schedule can be maintained, when will the loan be fully paid? (b) Assuming the same payment schedule, how large a loan could be paid off in exactly 20 years? The 10th reads: Quote from: 10th edition 12. A recent college graduate borrows$150,000 at an interest rate of 6% to purchase a condominium.
Anticipating steady salary increases, the buyer expects to make payments at a
monthly rate of 800 + 10t, where t is the number of months since the loan was made.
(a) Assuming that this payment schedule can be maintained, when will the loan be fully
paid?
(b) Assuming the same payment schedule, how large a loan could be paid off in exactly
20 years?
A comparison of chapters 7, 9, 5, and 6 will be posted next week.
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Jason Hamilton on January 22, 2013, 11:06:46 PM
Thanks a lot Brian and yanyuan!! I'm surprised how little effort the publisher put into "updating" the new edition haha
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Yanyuan Jing on January 23, 2013, 12:11:33 AM
Hey guys,

*EDIT*
Here are the differences in the homework questions for those using the 9th Edition. Since there aren't that many changes, I won't bother retyping all the individual question numbers, so I guess you can all refer to this page for specifics: http://www.math.toronto.edu/courses/mat244h1/20131/homeassignments.html

PLEASE NOTE: We didn't check ALL the questions in the textbook, only the suggested ones listed in the above link.

Sections 1.1-2.2: same
Section 2.3 had one difference, which Brian has already posted (see 2 posts above)
Sections 2.4-3.3: same.
Section 3.4: 6, 14, 22, 27, 43
Section 3.5: 2, 12, 13, 22, 25
Section 3.6-4.2: same
Section 4.3: #19 does not have any parts (it doesn't have parts in the 10th edition either...)
Section 4.4: #1, the restriction is $$-\pi/2 < t < \pi/2$$

Brian and I are meeting up next week to do the rest of the suggested problems. I'll update this post when we do!
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Victor Ivrii on January 23, 2013, 07:51:02 AM
Good job, Brian and Yanyuan. I think you need to state explicitly that you are comparing only problems given as a home work, not all problems in general (may be I am mistaken).
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Jingwei Chen on January 23, 2013, 09:46:52 AM
Great job! Thank you so much guys!
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Yanyuan Jing on January 23, 2013, 02:16:06 PM
Good job, Brian and Yanyuan. I think you need to state explicitly that you are comparing only problems given as a home work, not all problems in general (may be I am mistaken).

Thanks for the suggestion, Dr. Ivrii. I added a clarification in my previous post.
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Yanyuan Jing on January 30, 2013, 02:14:52 AM
Hey guys,

Here are the suggested questions for those using the 9th edition. Again, I only compared the suggested problems listed on the course website, not all the questions in the textbook.

Sections 7.1-7.7: same
Section 7.8: 4, 5, 16, 18, 20, with the following changes to #18:

Quote from: 10th edition
(c) Equation (iii) is satisfied if Î¾ is an eigenvector, so one way to proceed is to choose Î¾ to be a suitable linear combination of Î¾(1) and Î¾(2) so that Eq. (iv) is solvable, and then to solve that equation for Î·. However, let us proceed in a different way and follow the pattern of Problem 17. First, show that Î· satisfies $$(A-I)^2Î·=0$$ Further, show that (A-I)2=0. Thus Î· can be chosen arbitrarily, except that it must be independent of Î¾(1) and Î¾(2).
(d) A convenient choice for Î· is Î·=(0, 0, 1)T. Find the corresponding Î¾ from Eq. (iv). Verify that Î¾ is an eigenvector.
(f) Form a matrix T with the eigenvector Î¾(1) in the first column and with the eigenvector Î¾ from part (d) and the generalized eigenvector Î· in the other two columns. Find T-1 and form the product J=T-1AT. The matrix J is the Jordan form of A.

(Note: 18(e) is unchanged)

Section 7.9: same
Sections 9.1-9.6: same
Section 9.7: same, with slight difference in the prompt

Quote from: 10th edition
Determine all periodic solutions, all limit cycles, and the stability characteristics of all periodic solutions.

Sections 5.2-5.5: same
Section 6.1: Questions 21-24 in the 10th edition are not included in the 9th edition, and #27 is actually #23 in the 9th edition. Here are questions 21-24:

Quote from: 10th edition
21. $$f(t)= \left\{\begin{array}{ll} 1, & 0 \le t < \pi\\ 0, & \pi \le t < \infty \end{array} \right.$$
22. $$f(t)= \left\{\begin{array}{ll} t, & 0 \le t < 1\\ 0, & 1 \le t < \infty \end{array} \right.$$
23. $$f(t)= \left\{\begin{array}{ll} t, & 0 \le t < 1\\ 1, & 1 \le t < \infty \end{array} \right.$$
24. $$f(t)= \left\{\begin{array}{ll} t, & 0 \le t < 1\\ 2-t, & 1 \le t < 2\\ 0, & 2 \le t < \infty \end{array} \right.$$

Section 6.2: #35 is #34 in the 9th edition. Also, the prompt for #25 should read:
Quote from: 10th edition
A method of determining the inverse transform is developed in Section 6.3. You may wish to refer to Problems 21 through 24 in Section 6.1.

That's all! Hope that's helpful for everyone using the 9th edition!

P.S. This is my first time using LaTeX/MathJax. Please let me know if there are formatting/coding improvements I can make :)
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Victor Ivrii on January 30, 2013, 05:03:03 AM
Amazing job!

I noticed you typed bold $\xi$ without using MathJax and this was a correct decision as you wanted bold and upright.

Unfortunately MathJax does not support upright Greek fonts (LaTeX does through package upgreek)
Title: Re: Comparison of 9th and 10th textbook editions
Post by: Victor Ivrii on January 30, 2013, 05:18:38 PM
Added 4 numbers to sect. 3.3 of home assignments (in red). Please check them (9th vs 10th)