Science:Math Exam Resources/Courses/MATH105/April 2011/Question 04/Hint 1

The market equilibrium is defined to be the intersection point of the graphs of the demand function and the supply functions.

If $D(q)$ denotes the demand function as a function in the quantity $q$ and if the market equilibrium is given by the point $(q_{e},p_{e})$, then the consumer surplus is given by the formula

$\int _{0}^{q_{e}}\left(D(q)-p_{e}\right)\,dq$

See the wikipedia page on Economic surplus for more information about the market equilibrium and the consumer surplus.