Math 131, Spring 2004
Quiz #7, Discussion Section A (Thursday, 11:00-12:00)
Quiz problems should be solved using the methods discussed in this course. A calculator is rot
permitted. To receive full credit, show enough work to make it clear how you got your answer.;
Name:A-nSWf'r
~.eJ---
ill#
i
1. A ladder 10 feet long rests against a vertical wall. Let 8 be the angle between the wall and the
ladder. The bottom of the ladder is sliding away from the wall at a rate of 2 feet/sec. How fast is
8 changing when the bottom of the ladder is 6 feet from the wall?
d.~
~
d&
\l'Jo..n+ "'d:f
@
x
"')( \. &
S\y) e =-
-
")(
cos-e
X==::(c;)
a:>6~='
de~ -d~
-L
\0
\O'~
-
\0
~
de,. ::-;
--r d*
A=~
\D ~
x.o::::;.Co
.2
.~
10
-\
4-
2. Sketch the graph of a function whose domain is NOT (-00,00) that has no absolute maxifium
or absolute minimum.
:j
Math 131, Spring 2004
Quiz #7, Discussion Section B (Tuesday, 12:00-1:00)
Quiz problems should be solved using the methods discussedin this course. A calculator id ~ot
permitted.
Name:
To receive full credit, show enough work to make it clear how you got your answet.1
AnSWe.r- Ke~
ill#
J
1. A cake is put in an oven whose temperature is 3500 F. After t hours, its temperature T =
350 - 200e-t. Use differentials to estimate the change in temperature of the cake during the :lirst
0.2 hour. What is the expression for the exact change?
:::..2co e' --bdt
So
exact c.Yn~
..
- 200 - ,2DO
.eo~
~'o.a5
~
2. A ladder 13 feet long rests against a vertical wall. The bottom of the ladder is sliding away ~om
the wall at a rate of 5 feet/sec. How fast is the top of the ladder sliding when the base is 12 feet
from the wall.
d')( -- c-..,)
d~-
6 \ven
.Q::J.-
\No...r)+
d..-t
x.'2- +-'i
KV'\o\l\l..):
)( ~ l2-
0...+
7
=-
\3'2..
=d
~
~
d.~
~
~~
x~\2
50
~'=
ol~
~
'f
,,7--=-
~
ct.'*:
~'2--\'2.2.
=-) 'I -:. S
f-:>r/s~
~
Math 131, Spring 2004
Quiz #7, Discussion Section C (Thursday, 12:00-1:00)
Quiz problems should be solved using the methods discussedin this course. A calculator
permitted.
i.'J
!not
To receive full credit, show enough work to make it clear how you got your answerj
K~
Name: A-rIs.k)fX"--
ill#
-
,
,
1. A ladder 10 feet long rests againsta vertical wall. Let e be the anglebetweenthe wall and,the
ladder. The bottom of the ladder is sliding awayfrom the wall at a rate of 2 feet/sec.How f~ is
e changingwhenthe bottom of the ladder is 6 feet from the wall?
d&
~
X.1er1 ~
~'!
~
X=-Co
\0
S\nEJ-- x.
1(:>
"1
)<
\0
"=:?r de~-=
c""
)(.-::::.(0 ~
e- ";::.
d:t'"
~
~
~ -= ~ lO2...
--<02.
-:q. ~
-\OCt)5lO
-)
~,
-=-M
~B
~
2. Sketch the graph of a function that has a local maximum and a local minimum, but no absolute
minimum.