Main content

## 8th grade

- Recognizing linear functions
- Linear & nonlinear functions: table
- Linear & nonlinear functions: word problem
- Linear & nonlinear functions: missing value
- Linear & nonlinear functions
- Interpreting a graph example
- Interpreting graphs of functions
- Linear equations and functions: FAQ

Interpreting a graph example

Learn to interpret the graphs of a linear functions. Created by Sal Khan.

## Want to join the conversation?

- can u plz give more examples because every problem isn’t always worked out the same as this one(59 votes)
- I know right with my problem it is exactly what you mean.(10 votes)

- they need more examples I still don’t understand what to do cause all I get for an example is this none of the questions are like this.(35 votes)
- Math reminds me of doing homework….. Non-existent…(17 votes)
- please more examples this program makes no sense(13 votes)
- Man, I still don’t get this I need someone to explain it more clearly – not saying that sal doesn’t do a good job. Like I don’t get how athe said we move 1 in the x-direction we move -1 in the y direction 0:41(6 votes)
- To find the slope of a line you need to look at the rise over run.If a line is tilted to the right the slope will be positive and if its going to the left it will be negative. to find the slope he is looking for points that the line goes through, you don’t always only move 1 unit it depends on how far apart the points are. for easier viewing some people draw whats called a triangle. This shows two points that the line goes through. The triangle will also make it easier to look at the rise (y) over run (x).(7 votes)

- how do you interpret a graph(8 votes)
- Yes, this video is given as the “help” on a question with a loopy radio frequency type line that asks for “y-intercept”, “smallest possible x-intercept”, and listing the items in negative x territory as fractions of pie. Not so helpful…(7 votes)
- This so confusing I don’t understand any of it can someone help me? Please.(6 votes)
- i really want to, but i cant help you without showing you 🙁 all i can say is just follow the number line and go up down left right until you stumble upon a part of the graph line.(2 votes)

- is mayonnaise an instrument(4 votes)
- Depends on your definition of music.(4 votes)

- IDK why math makes me feel like i have one brain cell(5 votes)

## Video transcript

The illustration below shows the graph of y as a function of x. So that’s this graph right over here. And then they start to ask us some questions. Complete the sentences based on the graph of the function. So this axis is our y-axis, the vertical axis. Horizontal axis is x-axis. Initially, as x increases– so let’s think about it. Initially, so when we start from x equals 0 and x is increasing, what’s happening to y? Well, y is decreasing. So y decreases. So as x increases initially, y decreases. The slope of the graph is equal to blank for all x between x equals 0 and x equals 3. So x equals 0 and x equals 3, what’s the slope? Well, every time we move 1 in the x direction, we move down in the y direction. We go negative 1 in the y direction. Move up 1 in the x direction, we go negative 1 in the y direction. So our change in y over our change in x– our change in y is negative 1 whenever our change in x is 1. So our change in y over our change in x, which is the definition of slope, is negative 1/1. So it’s negative 1. And we see that. Every time x increases by 1, y decreases by 1. Starting at x equals 3, y blank as x increases. So starting at x equals 3, y increases as x increases. As x increases, y is increasing. So y increases as x increases. The slope of the graph is equal to blank for x between 3 and 5. So when x increases by 1, y is increasing by 3. So change in y is 3, change in x is 1. Slope is change in y over change in x, which is 3/1. So the slope here is 3. Every time x increases by 1, y increases by 3. For x between x equals 0 and x equals 4, y– let’s see, we can pick less than or equal to, greater than or equal to, or equal. So for x equals 0 and x equals 4, y is less than or equal to 0. So let’s do less than or equal to 0. And then they say, for x between x equals 4 and x equals 8– well, then y is greater than or equal to 0. So let’s make sure that we didn’t make any careless mistakes here. Let’s check our answer. We got it right.