Calculus
posted by Carl .
C(x) = 16x^(1/2) + x^2/1000
Find x to meet the minimum cost

Find the derivative, set equal to zero and solve for x
find C(x) 
at x = 0
I think you have a typo probably.
As shown this function starts at zero and keeps getting bigger forever.
Did you leave a negative sign out? 
No, there's no typo. That's what I can't figure this out. I put zero and it's wrong.

Beats me Carl.