Problema Solution

Company ABC produces widgets. They have found that the cost, c (x), of making x widgets is a quadratic function in terms of x. The company also discovered that it costs $23 to produce 2 widgets, $55 to produce 4 widgets, and $247 to produce 10 widgets. What is the total cost of producing 8 widgets?

Answer provided by our tutors

c(2) = 23

c(4) = 55

c(10) = 247


c(x) = a (x^2) + b(x) + c


Plugging in the points,


EQ1 23 = 4a + 2b + c

EQ2 55 = 16a + 4b + c

EQ3 247 = 100a + 10b + c


Now that you have three equations and three unknowns, its fairly simple to find the terms a, b and c.


From EQ1


EQ1i a = (23 - 2b - c) / 4


Plug that into EQ2


55 = 16[(23-2B-C)/4] + 4b + c

55 = 92 - 8b - 4c + 4b + c


4b + 3c = 37


EQ2i b = (37 - 3c) / 4


*I'm not a fan of giving away the entire answer, as I'm pretty sure you are not doing this as a recreational activity, and it's probably your homework, so this should serve as a "how to";


Combining EQ1i, EQ2i & EQ3 should yield values for a, b & c.


Putting those values into the quadratic equation, gives you the relationship of cost to widget production.


Plug in 8 as x, and you should get the cost.