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| Question 192693This question is from textbook Intermediate Algebra
 :  Recall that total profit P is the difference between total revenue R and total cost C. Given R(x)=1000x-x^2 and C(x)=3000+20x, find the total profit, the maximum value of the total profit, and the value of x at which it occurs. 
This question is from textbook Intermediate Algebra
 
 Answer by nerdybill(7384)
      (Show Source): 
You can put this solution on YOUR website! Recall that total profit P is the difference between total revenue R and total cost C. Given R(x)=1000x-x^2 and C(x)=3000+20x, find the total profit, the maximum value of the total profit, and the value of x at which it occurs. .
 Profit = Revenue - Cost
 f(x) = R(x) - C(x)
 f(x) = (1000x-x^2) - (3000+20x)
 f(x) = 1000x-x^2 - 3000 - 20x
 f(x) = -x^2 + 980x - 3000
 .
 By looking at the coefficient associated with the x^2 term (-1), we know that it is a parabola that opens downward.  Therefore, finding the vertex will provide the answer:
 .
 To do this, manipulate the equation into the "vertex form":
 y= a(x-h)^2+k
 .
 f(x) = -x^2 + 980x - 3000
 f(x) = (-x^2 + 980x) - 3000
 f(x) = -(x^2 - 980x + __ ) - 3000
 f(x) = -(x^2 - 980x + 240100) - 3000 + 240100
 f(x) = -(x+490) + 237100
 .
 maximum value of the total profit: $237100
 value of x at which it occurs: -490
 
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