在完全竞争市场profit是如何被定义的.doc

在完全竞争市场profit是如何被定义的？ 原题是 Explain how profit is determined in perfect competition? Perfect competition is the state that there are many firms selling homogeneous product, so neither the seller nor the buyer can control the price. Both parties are the price taker. In short run, it is possible for the firm to make a profit. The price is determined by the intersection point of the demand and supply curve. Since the market price is fixed. AD curve is representing the MR curve. When MR=MC. the profit will be maximized. Not all the firms are making profit in short run, some be just at the break even point, some even suffer from a loss. Depends on the position of their short run cost curve. However, in long run, the profit enjoyed by the firm rarely maintained. Because there may be some new firms entered into the market. Thir entry will lower the price and shift the demand curve down. Finally, the demand curve will touch the AC cuve at its lowest point.And leading the firm to make zero profit. My explain may not be so clear enough.. This topic may really take you some time and effort to understand... Hope it can really help you :-) 请教2道关于完全竞争市场厂商均衡的计算题 三、(完全竞争市场的厂商均衡)一个完全竞争企业的短期总成本TC=100-200q+q*q ，试求：（15分） 1、该厂商的可变成本曲本（VC）平均成本曲线（AC）、平均可变成本曲线（AVC）、边际成本曲线（MC）。 2、若产品的市场价格为p=10 ，求厂商利润最大化的产量。 3、当市场价格p 低于多少时，厂商将不会生产。 四、（完全竞争市场厂商均衡）设某产品生产的边际成本函数是MC=3q*q+8q+100 ，如果生产5单位产品时总成本是955，试求：（15分） 1、总成本函数和可变成本函数？ 2、价格为p=150 时，厂商利润最大化的产量为多少？ 1.VC=TC-FC=-200q+q^2,AC=FC/q=q-200+100/q,AVC=VC/q=q-200,MC=dTC/dq=2q-200 2.profit=pq-TC=10q-100+200q-q^2,对q求导，极值点q=105 3.pAVC最低点停止生产,AVC=q-200,即q200时，可变成本为负，固即便价格为零，厂家也不会停止生产。 1.TC=∫MCdq=q^3+4q^2+100q+C,由q=5时，TC=955得C=230 TC=q^3+4q^2+100q+230 2.150=P=MC=3q^2+8q+100得q=3（近似解） 请教需求的价格弹性的2道计算题 一、（需求的价格弹性）假设市场消费者对葡萄酒的需求函数为p=100-4q ，试计算：（15分） 1、p=10 、p=30 和p=60 时，需求的价格弹性系数|Ep| 2、价格为多少时，需求的价格弹性为单位弹性（|Ep|=1) 3、当市场价格处在什么情况下时，厂商提高价格会有利可图。 二、（需求的价格弹性）假设市场需求曲线为D(p)=100-20p+5w，其中w消费者收入。市场供给曲线为S(p)=10p 。试求：（15分) 1、当w=5 ，