Answer:
above $11
They will produce 9 units
the economic profit will be of zero at equilibirm
the firm will stay as they are achieving economic gains
in the long run the firms will produce 6.36 units
Explanation:
To find equilibriuem we qualize marginal revenue (slaes price) and marginal cost)
To produce at least 1 unit (positive outcome)
the companies will need when, q = 1 at a price of:
MR = MC
MR = 9 + 2(1) = 11
if the market price is $27 then:
27 = 9 + 2Q
(27-9)/2 = Q
Q = 9
27 x 9 - (81-9(9)+9^2)
243 - (81 + 81 + 81) = 243 - 243 = 0
In the long-run the company will produce when average cost matches marginal cost
Average cost = Marginal Cost
(81 + 9q + q^2)/q = 9+2q
81 + 9q = (9 + 2q)*q
81 + 9q = 9q + 2q^2
-2q^2 + 81 = 0
We solve with the quadratic formula to get the roots
q = 6.36