- 06.21
- H3 available. H3 marking scheme.
Comments from TA:
- I marked question 1, 2, 4, 5, 6, 7, 9, 10, and 11. Attached is the marking
scheme detailing where I give points, in case any student asks.
- List of sections for final exam posted.
- 06.20
- Revised Office hours after end of term:
- Tsai: 1:30pm-2:30pm, Friday June 22, Tuesday June 26, and Wednesday June 27.
- TA David Kong: 10am-noon, Monday June 25, Math Annex 1118.
- Practice final exams posted. Practice 6 revised.
- Students are encouraged to complete the teaching evaluation surveys on the CoursEval
website, https://eval.ctlt.ubc.ca/science
before the surveys close at 11:59 PM on June
24, 2018. You login to the site using your CWL. Survey results will not be released to
instructors until course grades have been submitted.
- 06.18
- Office hours after end of term: 1:30pm-2:30pm, Friday June 22,
Monday June
25,
and
Wednesday June 27.
- 06.15
- The average of MT2, the second midterm exam, is 30.4 out of
45, or 68%. It is slightly lower than my target 70%. The standard
deviation (Std Dev), 17%, is roughly the same as last year and MT1. For
comparison, the distribution of MT1 is included in the following table and
chart.
|
0-5 |
6-10 |
11-15 |
16-20 |
21-25 |
26-30 |
31-35 |
36-40 |
41-45 |
total |
average |
max |
Std Dev |
MT1 |
0 |
0 |
2 |
2 |
14 |
13 |
27 |
22 |
17 |
97 |
33.3 or 74% |
45 |
16% |
MT2 |
0 |
0 |
2 |
7 |
14 |
23 |
26 |
12 |
10 |
94 |
30.4 or 68% |
45 |
17% |
- Problem-wise statistics:
|
Q1 |
Q2 |
Q3 |
Q4 |
Q5 |
Q6 |
MT2 |
max
|
10 |
5 |
6 |
8 |
10 |
6 |
45 |
average |
6.7 |
2.5 |
3.2 |
6.4 |
8.0 |
3.7 |
30.4 |
average % |
67% |
50% |
54% |
80% |
80% |
61% |
68% |
Std Dev |
30% |
29% |
36% |
23% |
21% |
23% |
17% |
- 06.14
- MT2 solution posted. MT2 will be returned tomorrow.
- 06.11
- H2 available. H2 marking scheme.
Comments
from
TA:
- I have finished marking homework 2 and it is out of 39. I marked
questions
1,3,4,6,7,8,10,11,13,14,15, and 16. Overall it is done quite well. Most
students l$
2-3 marks due to computational errors.
- H3 and practice 5 posted. Note that H3 is due next Monday, so that we can
retu$
it on next Thursday.
- 06.07
- The second midterm exam (MT2) next Wednesday (June 13) will use the
entire
lecture time, 50 minutes. Its format will be similar to MT1.
It will cover
sections
1.9, 2.1-2.3, 2.5-2.6, 3.1-3.2, and 4.1.
For your preparation, practice 4 and old MT2 have been posted.
The solution to 2017 MT2 will be posted in the weekend.
- 06.04
- There was a typo on the end time of the final exam. It is now
corrected. It should end at
6pm, not 5pm. The total exam time is 150 minutes.
- 06.01
- Repost final exam info: Our final exam will occur on Thursday June 28,
3:30pm-6pm, in LSK
200.
- The average of MT1, the first midterm exam, is 33.3 out of
45, or 74%. It is slightly higher than my target 70%. The standard
deviation (Std Dev), 16%, is roughly the same as last year. The solution to mt1
is
posted.
|
0-5 |
6-10 |
11-15 |
16-20 |
21-25 |
26-30 |
31-35 |
36-40 |
41-45 |
total |
average |
max |
Std Dev |
MT1 |
0 |
0 |
2 |
2 |
14 |
13 |
27 |
22 |
17 |
97 |
33.3 or 74% |
45 |
16% |
- Problem-wise statistics:
|
Q1 |
Q2 |
Q3 |
Q4 |
Q5 |
Q6 |
MT1 |
max
|
6 |
9 |
8 |
8 |
8 |
6 |
45 |
average |
5.4 |
7.3 |
6.2 |
6.1 |
4.4 |
4.0 |
33.3 |
average % |
89% |
81% |
78% |
76% |
55% |
66% |
74% |
Std Dev |
18% |
19% |
27% |
30% |
40% |
19% |
16% |
- 05.31
- The first midterm exam will be returned on Friday June 1. The marking is done,
but $
need to record the marks and do the statistics. Note that June 1 is the "last day
for
withdrawal from most Summer Session Term 1 courses with withdrawal standing of W
recorded on a
student's academic record."
- 05.28
- The first midterm exam has 6 problems now, see MT1 page 1. The last one is Yes/No
with
no reason. Some other problems are Yes/No with reasons.
- H1 available. Uncollected homework/exam will be placed in a box outside of my
office.
- H1 marking scheme. Comments from
TA:
The homework is marked out of 39. A detailed marking scheme is pushed onto the
cloud and also attached to this email in case students ask where they lost marks.
This one is pretty easy so most students got nearly perfect scores. Some
observations are:
- When doing row reduction, a majority of students wrote out
the row operations explicitly, ex. R1+0.5R2, R3+R1,... which I believe are for
demo purposes during lectures only
(Reply from Tsai: Actually I did ask them to mark the row operations explicitly
and briefly. One way is to write
R1 -> R1 + 0.5R2,
another way is to draw an arrowed curve from R2 to R1 and write "x(1/2)" along
the curve. Sometimes I did 2 row operations together in one step, like
R1 -> R1 + 0.5R2,
R3 -> R3 - R2
- A few students are confused about
consistent/inconsistent and cannot determine which situation corresponds to which
- Lots of silly calculation mistakes, especially in row reductions and T/F
- Our final exam will occur on Thursday June 28, 3:30pm-6pm, in
LSK
200.
- 05.25
- The first midterm exam next Wednesday (May 30) will cover sections 1.1-1.5
and
1.7-1.8.
- 05.23
- The location of the TA office hours, 2-4pm Tuesdays, will be moved to
Math Annex 1118 (MATX 1118), starting next Tuesday. Our TA, David
Kong, told me that the office hour location yesterday, LSK 300B, was shared by
several classes and hence was a bit noisy and hard to identify our class. Math
Annex 1118 will be for MATH 221 only. I encourage you to attend the TA office
hours since David is very good and dedicated. He is also younger and
understand you better than me.
- First midterm Exam next Wednesday (May 30) will use the entire lecture time, 50
minutes. For your preparation, I have posted practice 2 and two old midterm exams.
The format of our first midterm exam next week will be similar to the 2017 exam,
with 4 computation problems and one Yes/No problem. The Yes/No problem will have 6
questions with no need of justification. I will announce the topics to be covered
on Friday. The solution to the 2017 exam will be posted in the weekend. Please read
carefully "Rules for the exam" in the first page of the 2017
exam.
- 05.16
- Because Lay's textbook is not in UBC bookstore yet, I've stored a pdf file
of the first chapter of Lay's book, 3rd edition, in a cloud server hosted at UBC
Math. Registered students will soon receive an email with its link,
which will expire on
2018-07-16. If you are not registered and want the link, please email me.
- There are many free online textbooks on linear algebra. The book
by Jim Hefferon, Linear
Algebra, is a well-known open-source textbook and has
lots of good exercises.
- Because next Monday is the Victoria Day, we will hold an additional office
hour this Friday, May 18, 3-3:50pm.
- 05.14
- Welcome to MATH 221 !
Check this page frequently regarding any announcement for the course.
- Please read the
course outline carefully.
- Email after lecture:
Dear MATH 221 students,
I am very sorry for the power disruption during today's lecture. It was an
issue for the entire Buchanan A building, and it was unclear when it could be
fixed. Hence it was simpler to cancel today's lecture. We will start on the
Wednesday lecture from where we stopped today. We will not schedule a make-up
lecture since it is nearly impossible for a class of 119 students. As a result,
we may skip a section near the end of the course.
Note, however, my office hours will start today at 3pm, and tomorrow at 1pm.
Please get yourself familiar with the course homepage
http://www.math.ubc.ca/~ttsai/courses/221-18Q2/
Another issue found after today's lecture is that the textbook by David Lay was
not ordered at the UBC Bookstore. I've contacted the MATH office to order the
book, but it may take a week. Please note that, although my lectures will
follow the book closely, you don't really need the exact book as the
assignments/solutions will be typed and posted in the course homepage. For your
study, it is better to read a textbook in addition to my lecture notes. I will
try to find some free online textbooks and let you know on Wednesday. I also
encourage you to look for Lay's book in the used books market. The third UBC
custom edition has been used by UBC for many years and should have a big
supply.