Answer:C' = 7-230000/x^2
Explanation:
Min occurs when C'=0
0=7-230000/x^2
230000/x^2=7
230000=7x^2
32857.128 = x^2
181.265 = x
Out of range.
So the min must be at an endpoint.
C(1) = 7+230000 = 230007
C(100) = 700+2300 = 3000
Since C(100)<C(1), C(100) is the minimum on the interval [1, 100]
The order size that will minimize cost is 100 units.