The monthly cost C of producing x widgets in dollars is mode
     The monthly cost C of producing x widgets (in dollars) is modeled by the function shown below.  C(x) = 2500 + 4.8 x + 0.002 x^2  In this model 2500 represents fixed monthly costs and 4.8 is the individual cost of each unit being produced. The term 0.002x^2 represents additional costs that are significant only when the production level x is large. Such costs might include additional machinery, time-and-a-half pay, etc. If the maximum monthly cost the company can sustain is $10, 500, determine the maximum production level. Round your answer down to the next whole number. 
  
  Solution
Answer :
The monthly cost c of produce x widgets(in dollars) is modeled by the function
C(x) = 2500 + 4.8x + 0.002x2 ------------------ ( 1 )
The maximum monthly cost the company can sustain is $ 10,500
Substitute C(x) = 10,500 in ( 1 ) we get
10,500 = 2500 + 4.8x + 0.002x2
0.002x2 + 4.8x - 8000 = 0
dividing by 0.002 on both sides of the equation , we get
x2 + 2400x - 4,000,000 = 0
Now solve for x we get x = 156-46

