<p>I have just been introduced to the topic of supply and demand curves in my mathematical modelling course. When we read the curve, we often say &quot;an increase or decrease in the price results in so and so happening.&quot; My issue with this is that we tend to interpret the graph by analysing it in both directions (i.e., right to left and left to right), unlike the way we typically read the graph of a function, which is left to right. An example is when we look at rate of change or concavity.</p>
<p>Why is it that we can read the supply and demand curve in such a way since it has been graphed using functions? What am I missing?</p>
<p><a href="https://i.sstatic.net/xzJT5ziI.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/xzJT5ziI.jpg" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2024-10-08T11:42:00.233Z
What do you mean with "analysing it ... right to left"?
VARulle
CC BY-SA 4.0
2024-10-08T11:51:09.817Z
@VARulle if we want to look at how price changes with quantity decreasing, then we are looking at the graph from right to left instead of the typical way we look at graph which is left to right
Oofy2000
CC BY-SA 4.0
2024-10-08T13:39:57.263Z
It's true for every graph that if you study what happens if the value on the horizontal axis *decreases* you have to read it "right to left". The only unusual thing in this graph is that the dependent variable (quantity) is on the horizontal instead of the vertical axis, as it is the standard in mathematics. So it's reading "bottom to top" instead of "left to right" what one has to do.
VARulle
<mathematical-economics><supply-and-demand>
Reading and interpreting supply and demand curves
Oofy2000
# Reading and interpreting supply and demand curves

(Asked by: username_0 on 2024-10-07)

I have just been introduced to the topic of supply and demand curves in my mathematical modelling course. When we read the curve, we often say "an increase or decrease in the price results in so and so happening." My issue with this is that we tend to interpret the graph by analysing it in both directions (i.e., right to left and left to right), unlike the way we typically read the graph of a function, which is left to right. An example is when we look at rate of change or concavity.

Why is it that we can read the supply and demand curve in such a way since it has been graphed using functions? What am I missing?

[![enter image description here](https://i.sstatic.net/xzJT5ziI.jpg)](https://i.sstatic.net/xzJT5ziI.jpg)

**Tags:** mathematical-economics, supply-and-demand

> **Comments:**
> **username_1**: What do you mean with "analysing it ... right to left"?  
> **username_0**: @username_1 if we want to look at how price changes with quantity decreasing, then we are looking at the graph from right to left instead of the typical way we look at graph which is left to right  
> **username_1**: It's true for every graph that if you study what happens if the value on the horizontal axis *decreases* you have to read it "right to left". The only unusual thing in this graph is that the dependent variable (quantity) is on the horizontal instead of the vertical axis, as it is the standard in mathematics. So it's reading "bottom to top" instead of "left to right" what one has to do.  

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## 0 answers

