Suppose the total cost (in dollars) of manufacturing x units of a certain commodity is C(x)= 3x^2+ 18x + 243. At what level of production is the average cost per unit the smallest? At what level of production is the average cost per unit equal to the marginal cost?(adsbygoogle = window.adsbygoogle || []).push({});

So I thought if you want the average cost per unit to be the smallest- all you have to do is take the derivitave of C(x)= 3x^2+ 18x + 243, then solve for the minima which is at x=-3. But in this case, it doesn't make sense for the x value to be negative.

But for the second part, i lack knowledge in the area of economics, so i'm not sure what value they want when they ask for "what level of production is the average cost per unit equal to the marginal cost". Are they talking about inflection points? Help!!!

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# Minium cost=marginal costs?

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