About this video
The video plots ordered pairs such as (8, 10), (6, 10) and (5, 7). The first number is the x-coordinate (how far to move right) and the second is the y-coordinate (how far to move up). You can do the moves in either order, but you must not swap which number goes with which direction.
You'll be able to
- plot an ordered pair by moving right for the x-coordinate and up for the y-coordinate.
- explain why swapping the numbers gives a different point.
Key words
- ordered pair
- Two numbers in a set order, like (8, 10), that name one point.
- x-coordinate
- The first number; how far to move in the horizontal (x) direction.
- y-coordinate
- The second number; how far to move in the vertical (y) direction.
Transcript
We are asked to plot 8 comma 10. So the first number in this ordered pair, this is our x-coordinate. This tells us how far do we move in the x direction. It's a positive 8, so we move 8 in the x direction. And then the second number in our ordered pair is 10. That is our y-coordinate.
That tells us how far we move in the y direction. Since it's positive, we move up 10. So we move up 10, all the way over here. And you could have thought about it either way. You could have said, hey, look this is our y-coordinate. This is 10. So I could move up 10.
And then my x-coordinate is positive 8. So I'll move 8 along the positive x-axis, or I'll move 8 to the right. You see right over here I have moved 8 to the right-- 1, 2, 3, 4, 5, 6, 7, 8. And I have moved 10 up-- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. You might be tempted to move 8 up and then 10 to the right, which would put you there.
But then you would have had the two numbers mixed up. You would have had the x and the y-coordinates mixed up. The 8 tells you how far to move in the horizontal direction. The 10 tells you how far to move in the vertical direction. Let's do a couple more of these.
Plot 6 comma 10. Well once again, the first number in the ordered pair is the x-coordinate, how far we move in the x direction. So we move 6 to the right. And then the second number, the 10, tells us our vertical coordinate, our y-coordinate. So it's positive 10.
So we move 10 up. Let's do one more-- 5 comma 7. So my horizontal coordinate is 5, so I move 5 to the right. And then my vertical one is 7, or my y-coordinate is 7. So I move 7 up-- 1, 2, 3, 4, 5, 6, 7. And as long as you remember which one is horizontal and which one is vertical or which one is the x-coordinate and which one is the y, you should be fine.
You could say, hey look, this is my y-coordinate, 7. So I'm going to move 7 up. And my x-coordinate is 5, so I'm going to move 5 to the right. And it will get you to that exact same point. This specifies exactly one point in the coordinate plane.
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