Final answer:
A linear function may not be adequate for describing small pieces of the supply and demand graph due to the different shapes and elasticity of the curves.
Step-by-step explanation:
In the context of supply and demand graphs, a linear function may not be adequate when analyzing very small pieces of the graph. This is because supply and demand curves can have different shapes and slopes depending on their elasticity. Elasticity refers to how much one economic variable responds to changes in another variable. When a supply or demand curve is elastic, there is a large change in quantity in response to a change in price. Conversely, an inelastic curve shows only a small change in quantity when price changes.