原Po第一题有点不完整
每一个麦农有U形的平均总成本曲线
并达到LAC(min)=3，每位产出10单位
原本需求线是Q=3600-200p
Q*=3600-200(3)=3000
厂商家数=3000/10=300
然后，接着你的问题
P=MC=0.3q q=P/0.3
Q=300(p/0.3)=1000P
(新的需求线）
7200-200p=1000p P*=6 Q*=6000
P*=MC=0.3q q*=20
MC=0.3q 积分 TVC=0.15q^2
TC=0.15q^2+TFC
LAC=0.15q+TFC/q
对LAC微分得0 （MES)
0.15-TFC/q^2=0 q=10代入（MES)
得到TFC=15
兀=60*20-0.15(20^2)-15=45
※ 引述《claudina (claudina)》之铭言：
: Suppose demand shifts to Q(P)=7200-200P. If the number of farmers is fixed
: in the short run and each produces with a marginal cost given by MC(q)=0.3q,
: where q denotes the number of bushels produced. What is the profit a typical
: farmer makes?
: In the 1970s, people had become accustomed to high inflation in the United
: States. In 1979, the Fed decided to fight inflation and decreased the money
: supply growth rates. Many people thought that the Fed's action would cause a
: recession. Is thos thinking consistent with the aggregate demand and aggregate
: supply model? Explain.
: 假设某国的石油产业里只存在两家厂商, 其产品品质与生产技术完全一样. 并且,
: 两家厂商的固定成本为零, 每单位边际成本为14元. 若市场需求函数为P=50-0.001X,
: 其中X代表第1家厂商产量X1与第2家厂商产量X2的总和, 亦即X=X1+X2;并且,
: 这两家厂商均相信对方厂商的产量决策不会因为自己产量变动而有所改变. 请问:
: 当两家厂商勾结成联合独卖, 则均衡下的两家厂商产量与利润各为何?
: 请大家帮帮我!