Final answer:
The general Price-Demand relationship cannot always be expressed as a linear function; it varies depending on several factors and is often nonlinear as described by the law of demand.
Step-by-step explanation:
The statement that the general Price-Demand relationship can be expressed as a linear function is not entirely true. While it is possible for specific cases where the relationship between price and demand is proportional, the law of demand typically describes a nonlinear relationship in most real-world scenarios. According to the law of demand, a higher price leads to a lower quantity demanded, and a lower price leads to a higher quantity demanded, holding all other factors constant (ceteris paribus). This relationship is usually represented by a downward-sloping demand curve.
However, while the demand curve reflects the law of demand, it is not always linear. For example, constant unitary elasticity describes a situation where the price change is proportional to the change in quantity demanded, which could be represented linearly. But in general, demand curves can be linear or curved, depending on various factors that affect how sensitive demand is to price changes. For learning more about how demand, supply, and prices interact, one should consider the universal generalizations described by supply and demand graphs under the assumption of ceteris paribus.