The demand function of widgets is given by p 200 q 2 where
The demand function of widgets is given by p = 200 q 2 where p is the unit price in U.S. Dollars and q is the quantity of widgets demanded each week. If the supply function is p = q 2 + 38
Find
(a) the equilibrium price p and the equilibrium quantity q ,
(b) the producers’ surplus
(c) the consumers’ surplus
Solution
The demand function of widgets is given by p = 200 q 2 where p is the unit price in U.S. Dollars and q is the quantity of widgets demanded each week.
If tThe supply function is p = q 2 + 38
a) Equilibrium quantity is reached when demand=supply. 200 q 2 =q 2 + 38, q2=81 is the Equilibrium quantity
q* = 81. The price at q* is p*. Therefore, p* = 200-81=119
(b) the producers’ surplus
We know the equilibrium is 119, 81 is p*,q*, and supply is p2 = q 2 + 38,so, when q2=0 we have p2=38. and when p2=119 we have q2=81. So, 0,119 is projection of equilibrium point on Y axis. Producer\' surplus = 1/2 * (119-38)(81) = the producers’ surplus: 3280.5
c)the consumers’ surplus:
Demand curce is p = 200 q 2. considereing when q=0 , p=200. And at equilibrium p,q is 119,81. So Consumer\' surplus is .5*(200-119)(81) = 3280.5

