Math 2250 HW #7
Due 12:30 PM Thursday, September 26
Reading: Hass §3.6–3.8
Problems: Do the assignment “HW7” on WebWork. In addition, write up solutions to the
following problems and hand in your solutions in class on Thursday.
1. The following plot shows the graph of a function f (x) along with the graphs of f 0 (x) and
f 00 (x). Which is which? Explain your reasoning.
B
A
C
2. Let h(t) be the height of a falling ball at time t. If the ball is in freefall, the velocity of the
ball when the ball is at height h is given by
p
v(t) = k h(t)
for some constant k. Show that the acceleration of the ball is constant.
3. Shown below is the curve
x3 + y 3 − 9xy = 0,
which is known as the folium of Descartes. At what point other than the origin does the
curve have a horizontal tangent line?
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4
3
2
1
-5
-4
-3
-2
-1
1
-1
-2
-3
-4
-5
1
2
3
4
5