A firm operating in a purely competitive market has total cost function given by c(y) = y^ 2 + 10 for y > 0 and c(0) = 0.
(i) What is the firm’s marginal cost function?
(ii) What is the firm’s average cost function?
(iii) At what quantity is the firm’s marginal cost equal to its average cost?
(iv) In the long run, what is the lowest price at which the firm will supply a positive quantity?