III. The marginal cost function, in 100 of dollars, of the production of x units of trousers, 3x2 +12
where x is expressed in a thousand of units, with x € ]0,10), is given by f(x)
(6.5 pts)
1. Calculate f (5). Interpret this result in terms of cost.
2. Study the sense of variation of f and construct the table of variations of f.
3. For which production will the enterprise attain a minimum marginal cost? Find this
marginal cost.