document.write( "Question 798620: 3) The profit function for Wannamaker Trophies is \"P%28x%29+=+-0.4x%5E2+%2B+fx+-+m\", where f represents the design fee for a customer’s awards and m represents the monthly office rent. Also, P represents the monthly profit in dollars of the small business where x is the number of awards designed in that month.
\n" ); document.write( "a) If $80 is charged for a design fee, and the monthly studio rent is $1,600; write an equation for the profit, P, in terms of x.
\n" ); document.write( "b) How much is the profit when 50 award designs are sold in a month? Answer:
\n" ); document.write( "c) How many award designs must be sold in order to maximize the profit? Show your work algebraically.
\n" ); document.write( "d) What is the maximum profit?
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Algebra.Com's Answer #482319 by Finavon(81)\"\" \"About 
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a) \"P%28x%29+=+-0.4x%5E2+%2B+80x+-+1600+\"\r
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\n" ); document.write( "\n" ); document.write( "b) x=50
\n" ); document.write( "\"P=+-0.4%2A2500+%2B+4000+-+1600+=+1400\"\r
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\n" ); document.write( "\n" ); document.write( "c)
\n" ); document.write( "Graph function takes 3 pairs of numbers before the equation.
\n" ); document.write( "First pair define the size of the image on the screen (width then height).
\n" ); document.write( "Set this to see the graph on the screen.
\n" ); document.write( "Second pair are the range of values on the x axis (min then max)
\n" ); document.write( "Third pair are the range of values on the y axis (min then max)
\n" ); document.write( "You can calculate some vaues, but I just set these wide to see the function. Using (-1000, 1000) for both:
\n" ); document.write( "\"graph%28300%2C200%2C-1000%2C1000%2C-1000%2C1000%2C80x-0.4x%5E2-1600%29\"
\n" ); document.write( "Inspecting the result shows that the region of interest, (in this case the values where the maximum value of y occurs) lies at higher values of y (try -500,5000). The x values can be narrowed down (try -100,400).
\n" ); document.write( "\"graph%28300%2C200%2C-100%2C400%2C-500%2C5000%2C80x-0.4x%5E2-1600%29\"
\n" ); document.write( "Further adjustment (to -50,200,-300,2700) produces
\n" ); document.write( "\"graph%28300%2C200%2C-50%2C200%2C-300%2C2700%2C80x-0.4x%5E2-1600%29\"
\n" ); document.write( "Inspecting this shows the max lies around 100 sales
\n" ); document.write( "d)
\n" ); document.write( "Max Profit @ x=100 sales
\n" ); document.write( "P=-4000+8000-1600=$2400
\n" ); document.write( "That sale brought in $80 and cost 199/2.5 =$79.60
\n" ); document.write( "Next sale brings in $80 but costs 201/2.5=$80.40
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