# Wednesday, January 20 Announcements

```Wednesday, January 20
Announcements
WeBWorK #2 due this evening, 9pm
Solutions to (all versions of) Quiz #1 are online
Pick up your quiz papers in the Math Learning Centre
MLC is in the Klinck building (LSK), 3rd floor
Available from 10am to 6pm, Monday through Friday
Bring your student ID (and know we’re Section 211)
Get your quiz from the Quick Help desk
All details on the course web page
Wednesday, January 20
Clicker Questions
Clicker Question 1
Race to the top
Suppose we know:
R5
2 f (x) dx = 11
R5
2 g(x) dx = 7
R7
5 f (x) dx = 2
R7
5 g(x) dx = 3
y =f (x)
y = g(x)
2
3
A. 5 =
R5
2
(f (x) − g(x)) dx +
B. 14
C. 23
D. 3
E. none of the above
R7
5
(g(x) − f (x)) dx
4
5
6
7
Clicker Question 2
Solid of revolution
What is the general formula for the volume of the solid formed
by rotating, around the x-axis, the graph of y = f (x) between
x = a and x = b? (Assume f (x) ≥ 0.)
Z
b2
π(f (x))2 dx
A.
a2
Z
b
B.
πf (x) dx
a
Z
b
π(f (x))2 dx
C.
a
Z
b2
D.
πf (x) dx
a2
E. none of the above
Clicker Question 3
Another formula from geometry
What is the area of
an annulus with
R
r
A. π(R − r)2
C.
1
2 πRr
D.
B.
1
2 π(R + r)
π(R2 − r2 )
E. none of the above
```