Question

How do you find the slope of a demand curve ?

Answer 1

Hint: Slope is represented by ‘ m ’ . The slope can be calculated by finding the ratio of the “ vertical change ” we say graphically as the y-axis denoted by $ \vartriangle y $ = $ {y_2} - {y_1} $ , to the “ horizontal change “ we say graphically as the x-axis denoted by $ \vartriangle x $ = $ {x_2} - {x_1} $ , between the two different points on a same line . The formula of slope is $ m = \dfrac{{{y_2} - {y_1}}}{{{x_2} - {x_1}}}. $ The demand curve is a graphical representation of the relationship between the price of a good or service and the quantity demanded for a given period of time . The price is drawn along the y-axis and the quantity demanded on the x-axis .

Complete step-by-step answer:
It is very easy to find the slope of a demand curve if you know the concept of basic slope . As per finding the slope , we must divide the rise by run .
If we talk about a demand curve then that means there will be a ratio of the change in price ( that is $ \vartriangle y $ = $ {y_2} - {y_1} $ ) to the change in quantity demanded ( $ \vartriangle x $ = $ {x_2} - {x_1} $ ) .
Let's consider change in price as $ \vartriangle P $ = $ {P_2} - {P_1} $ .
Let's assume the change in quantity demanded as $ \vartriangle Q $ = $ {Q_2} - {Q_1} $ .
Slope of Demand Curve = $ \dfrac{{{P_2} - {P_1}}}{{{Q_2} - {Q_1}}} $ = $ \dfrac{{\vartriangle P}}{{\vartriangle Q}} $ .
Hence , by this you can find the slope of a demand curve .
So, the correct answer is “ $ \dfrac{{{P_2} - {P_1}}}{{{Q_2} - {Q_1}}} $ = $ \dfrac{{\vartriangle P}}{{\vartriangle Q}} $ .”.

Note: In order to find this slope , we need to take two different points but it has to be on the demand curve .
The ratio of ordered pairs must be fulfilled .
Remember that this phenomenon works only when there will be a linear demand curve .
Need to learn derivatives , as the slope is the derivative at the specific quantity value.