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# Graphing sequence relationships

Explore the concept of numerical patterns. Understand how to generate two sequences using given rules, identify relationships between corresponding terms, form ordered pairs from these terms, and graph these pairs on a coordinate plane.  Created by Sal Khan.

## Want to join the conversation?

• Is there a way to describe both sequences simultaneously in a single expression?
• Not really, because you need an equation to describe how x gives you y. To do this you need an equation. 5x by itself would be considered an expression. But that is not enough info to give you the sequence for getting y. You need the "equation" 5x=y to describe the sequences for x and y to plot them. Hope this helps. :)
• Can anybody tell me why x and y are traditional letters?
• because coordinate planes is normally used to represent data but when someone is using it with no data the axes are unknown so people use letters to represent the unknown so the axis x is unknown or not assigned and axis y is unknown or not assigned. so people use letters as a placeholder. I wish I helped
• Can someone help me? I can't figure out the following challenge Visualizing and interpreting relationships between patterns. If you see this please answer! Thanks for your time
• Think of the plot area as two number lines. The first number in an ordered pair goes to the right and the second number in an ordered pair goes number goes up. (Right UP!). Easy enough to plot on the graph. That's the easy part. The part you might be having problems with is finding out the relationship between the numbers.

Example

Sequence X: Start at the number 5 and the rule is add one. So sequence X would read 5, 6, 7, 8, 9 and so on.
Sequence Y: Start at the number 10 and the rule is add two. So the sequence Y would read 10, 12, 14, 16, 18 and so on.
Your ordered pairs would be (5,10) (6,12) (7,14) (8,16) (9,18)
Do you notice a pattern? 5x2=? 6x2=?
Could you say that the numbers on the Y axis are two times as large? I hope this helps some.
• what is a constant number? Please reply, I have a test tomorrow...
• A fixed value.

In Algebra, a constant is a number on its own, or sometimes a letter such as a, b or c to stand for a fixed number.

Example: in "x + 5 = 9", 5 and 9 are constants

If it is not a constant it is called a variable.

I think.
• Why X and Y and not any other letters?
• x and y are the traditional letters so when your starting out you can use whatever you want but later on, always use them because they can mean different things in algebra.
• Good video
• Can someone help me? I can't figure out the following challenge Visualizing and interpreting relationships between patterns. If you see this please answer! Thanks for your time
• Its really easy. All you do is enter in the box the data for the x and y axis
Example: y start 4, add 3
• what are inputs and outputs?
• Inputs are like things you put into a machine, and outputs are what the machine gives you back. For example, if you put in a number as an input, the machine might give you a different number as an output.
(1 vote)
• why does X go first? and how does this apply in real life?