Answer:
10. 5556 discs per month
11. 3.33 hours; 0.196%
Explanation:
I find "appropriate technology" for questions like these to be a graphing calculator.
10. Put the given function definitions into the formula for profit and look for the peak of the profit curve. It is found at x ≈ 5556.
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11. The peak of the graph is found at t=3.333. The value of A(t) there is about 0.1962.
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If these are part of a calculus course, you can find the maximum values by differentiating the P(x) or A(t) functions and setting the derivative to zero. You get a linear equation in each case, so finding the independent variable value is not difficult:
10. 5 -.0009x = 0
11. (.16 -.048t)e^(-.3t) = 0