Find the consumer surplus at the equilibrium.

Question

D(x)=1-4x; x=1

a)$2

b)$4

c)$8

d)$0

Answer 1

The terminology doesn't look right.

Demand is a function of price, a downward sloping curve or line.

D(P) = 1 - 4P or

Q = 1-4P or using x and y variables

x= 1-4y

-4y = x - 1

y = (-1/4)x + 1/4

That's a downward sloping line starting at (0,1/4) and intersecting the x axis at (1, 0)

Even if price were zero, consumer surplus would only be 1/8 of a dollar or 12 1/2 cents, the area below the demand curve and the x-axis and the y-axis. Since price is usually positive, >0, the consumer surplus will be between 0 and 12 1/2 cents.

d) $0 is the best answer, either correct, or at least closer to the correct answer than a, b or c.

Odds are though that the problem was not copied accurately.