The equation used to calculate the demand curve is Q=q1+q2...+qn or Q=f(P). Quantity demanded is represented by the variable "Q" while "q1" or "qn" correspond to an individual demand curve. The expression f(P) indicates that quantity demanded is a function of price, or "P."
The function that represents the market demand curve is the summation of all the individual demand curves. Therefore, Q=q1+q2...+qn=f(P). When plotted on a graph, the demand curve reflects an inverse relationship between price and quantity demanded. This is because the demand for a product or service usually decreases as the price increases. The demand curve is created by adding together the individual demands at each price point.