Quiz #6 (2.8 & 2.9)
Ckisslb:
Math 1210
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Name:
008 Fall 2012
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October 2, 2012
Score
Instructor: Katrina Johnson
Instructions: Complete each problem. Show all of your work as partial credit will be
given where appropriate, and there may be NO credit given for problems without
supporting work All answers should be completely simplified, unless otherwise
stated You may NOT use a calculator. You may use a 3x5 index card.
(15 pts) 1, The area of a circle is decreasing at a rate of 2 square feet per second.
Find the rate at which the radius is changing when the area of the circle is 49zr
square feet. (bon’t forget the units of your answerS)
/
/
.
Answer 1:
(10 pts) 2. Find dy, the differential of y, for y
3
—7x
+
2 —4
3x
dy=
(15 pts) 3. Use differentials to approximate
(Note: A calculate approximation
5 54772256 How similar is your approximation?)
j
for
\,
J