The marginal cost of producing the xth box of CDs is given by 9 − x/(x2 + 1)2. The total cost to produce two boxes is $1,100. Find the total cost function C(x).

C(x)=

Step-by-step explanation:

We are given that

Total cost function

C(x)=

Let

Substitute the value

Substitute x=2

Total cost function, C(x)=

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4