 Under the chapter of consumer behavior, we are going to study inverse demand curve. As we know that the consumer's demand of any commodity, either it is X, either it is Y, either it is Z, it depends upon its own price, price of the other goods and the income. And when we maintain the relationship between the quantity demanded and the price, we say that it is the demand curve. And being the direct demand curve that we mostly have studied up till now, we have seen that whenever there is any change in the price, there is that change reflected in the change in quantity demanded. So, any change in the price of the commodity will be reflected in the change of the commodity demanded. That will be the direct demand curve. But when we say the inverse demand curve, that does not mean that we are going to add certain things or either we are going to exclude anything. We are just going to make this relationship inverse. It means the factor that was first made responsible for the change, now it is being reversed. If we say that first we say that as the price of a share will change, then the price of the share will decrease or increase. And we call this relationship demand curve. But in this demand curve, if we have these two axes in the form of a graph or in the form of an equation, we just change their position. So, what will happen is that now quantity demanded will not be the dependent, rather quantity demanded it will become the independent. So, as we have already written that quantity demanded of a commodity, we write it in the form of an equation. So, we write that it is the function of price P and it is the inverse function of the P. And when we want to show the inverse, then in the form of an equation, we always apply the sign of negative. So, we write that quantity demanded of any commodity is equal to minus B P mean B is the perimeter or the coefficient of the price and to make it a equation, we add the constant. So, we say quantity demanded is equal to A minus B P. So, here A will be the intercept and B will be the slope that will reflect the change in quantity demanded with respect to change in price. That was our we say direct demand curve. When now we have to make it inverse, we will shift the positions of price and commodity demanded quantity with each other. Now price will come on the left side of the equation and price comes on the left side and it becomes the function of quantity demanded. So, now we will say that it will tell us the change in the price due to change in the quantity demanded. As we know that the mostly we have assumed and it is the rule that the price, the consumer is not going to affect. Mean the price that is prevailing in the market, either any type of the buyer is there, any number of the buyer is there, we say that we are not going to affect. Or if we say that the buyer can lower his demand but he cannot affect the price of the market in the general practices. Until he is a very big mean, which we will say that only one buyer can control the entire market, it will be an exceptional case. So, that will not be possible for a consumer. But since we are deciding the inverse thing mathematically, now the quantity will change and with the change in quantity demanded, what will be its response to the price of that commodity. For this, we keep the price on the vertical axis and the quantity demanded on the x axis and we draw the relationship of it. And this relationship we are saying that there is an inverse demand function, mean there is demand but now the position of explanatory variable has been given to the dependent variable. And in this way, we say now that our focus has changed from the price to the quantity demanded. Mostly, in our models, the explanatory variable is expressed on the x axis and the dependent variable is expressed on the y axis. So, in this inverse demand function, we have shown also now the quantity demanded on the x axis and the dependent on the y axis that is the price. And now this inverse demand function is actually our relationship of the direct demand function, it explains only that but it is only its positioning of dependent or explanatory variable reverses and the price here now it is being defined by the quantity demanded. Actually, inverse demand function has a very importance or the significance in the theory of the consumer and particularly in the market behavior. So, in the market, entrepreneur or producers get this help to understand that in what way the consumer who has the demand of his quantity if he does less or more than the quantity of his demand, then the price is actually not decreasing, he is expressing his willingness to pay and how it will give rise to the change or the willingness to pay of the consumer for that commodity in the market. And likewise, as a producer, we have to see how much revenue can be less or more, in that assessment also because we always see revenue as a total amount and what is the price of that amount. So, P into Q, so these two factors here when it is utilized with the help of inverse demand function, it provides a such solution to measure the marginal revenue for the consumers change in the quantity demanded and how the marginal revenue to the entrepreneur will change if the consumer will shift its demand from a particular point to any other point.