Friday, February 26 Announcements

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```Friday, February 26
Announcements
WeBWorK #7 is now open
Due Wednesday, March 2 at 9pm
Covers material from “Week 7”—see syllabus online
Quiz #3 solutions online; papers in Math Learning Centre
Quiz #3 grades:
Our section’s average 3/10. Quiz was longer than it should
have been; but I still wish we were doing better.
Problem #1 (sin-cos trig integral) should be a gimme.
Term marks scaled, so if we do well on the final, scores will
come up. Just make sure we learn from our mistakes!
If you think yours wasn’t graded right: check online
marking scheme first. Then hand me official “regrade form”
(quizzes web page) with your quiz paper, by next Friday.
Friday, February 26
Clicker Questions
Clicker Question 1
A massive undertaking
A lamina with density ρ = 4 is in the shape of the region
between the graphs of y = 1/x and y = (3 − x)/2. Find the
mass of the lamina.
A. 3 − 4 ln 2
The calcuation
B. ln 2 − 3/4
Setting the two functions
equal, we find that the graphs
intersect at x = 1 and x = 2.
So the mass is
Z 2
3−x 1
4
−
dx.
2
x
1
C. 3/4 − ln 2
D. 4 ln 2 − 3
E. none of the above
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