
Answer:
 a) r(q) = 1000(q +1/q)
 b) r'(q) = 1000(1 -1/q^2)
 c) r'(10) = 990
Step-by-step explanation:
a) Revenue is the product of quantity and price:
 r(q) = q·p(q) = q(1000(1 +1/q^2))
 r(q) = 1000(q + 1/q)
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b) The derivative is ...
 r'(q) = 1000(1 -1/q^2)
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c) The derivative evaluated for q=10 is ...
 r'(10) = 1000(1 -1/10^2) = 1000(0.99)
 r'(10) = 990