宏观经济问题,成本曲线
问题描述：
宏观经济问题,成本曲线
Suppose
the marginal cost of two plants of a firm areMC1= 5
+ 2y1andMC2= 40
+y2
(1)
How should the output be divided if the total output is 25?
(2)
What is the firm’s marginal cost curve?
答
1. y1 + y2 = 25
5 + 2*y1 = 40 + y2
解联立方程得
y1 = 20
y2 = 5
2. y = y1 + y2
MC = MC1 = MC2 = (MC1 + 2*MC2)/3 = [(5+2*y1) + 2*(40+y2)]/3
MC = 85/3 + 2*y/3MC = MC1 = MC2 = (MC1 + 2*MC2)/3 = [(5+2*y1) + 2*(40+y2)]/3 为什么 MC= (MC1 + 2*MC2)/3 ？ 还有，可不可以，先算出反函数，y1=MC1/2-2.5 ，y2=MC2-40然后，y1+y2=MC1/2+MC2-42.5 然后，，，我就不知道怎么样弄回MC了，因为有两个MC，一个MC1、MC2有一条代数定理，大概是初中学的，是这样的：如果a/b = c/d，则a/b = (a+c)/(b+d)。用在MC1 = MC2，设a = MC1b = 1c = 2MC2d = 2则MC1 = (MC1+2MC2)/(1+2) = (MC1+2MC2)/3用你的方法，记住MC1 = MC2 = MCy = y1 + y2 = (3/2)*MC -42.5解MCMC = 85/3 + 2*y/3