Question

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請問35、36怎麼解，希望有算式✍🏻，感謝！

b. What is the rate of change of the total cost when the
level of production is ten surfboards a day?
35. EFFECT OF ADVERTISING ON PROFIT The quarterly profit (in
thousands of dollars) of Cunningham Realty is given by
x in
= 3.5,
3.
alt of
P(x) = -*** + 7x + 30
=
-ered
en by
time
=
-
vhen
1
P( -x2 +
(0 < x < 50)
3
bos
where x (in thousands of dollars) is the amount of money
Cunningham spends on advertising per quarter.
a. Find P'(x).
b. What is the rate of change of Cunningham's quarterly
profit if the amount it spends on advertising is
$10,000/quarter (x = 10) and $30,000/quarter (x = 30)?
36. DEMAND FOR TENTS The demand function for Sportsman
5 X 7 tents is given by
p = f(x) = -0.1x2 – x + 40
where p is measured in dollars and x is measured in units
of a thousand.
a. Find the average rate of change in the unit price of a tent
if the quantity demanded is between 5000 and 5050
tents; between 5000 and 5010 tents.
b. What is the rate of change of the unit price if the quan-
tity demanded is 5000?
t (b).
=
own
at its
2.
time
s the

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