Thread: Marginal and Average cost functions

1. Marginal and Average cost functions

I cant seem to figure these out.
Find the marginal average cost function if the cost function is given by

C(x)= .04x^2 + 30x + 500

Then :

Find the absolute minimum of this average cost function
C(x) = .01x^2 + 10x + 400 all divided by x

2. C(x) is the cost for producing x units, therefore, the cost for producing 1 unit is given by C(x)/x
And the marginal for average cost is just the derivative of C(x)/x

3. Find the absolute minimum of this average cost function
C(x) = .01x^2 + 10x + 400 all divided by x

Do not understand find the minimum of this average cost