How to Plot Points on the Coordinate Plane

0:02 Coordinate plane explained clearly. By the end of this video, you should be able to understand what the coordinate plane is, know the x-axis and the y-axis, understand ordered pairs, plot points correctly, understand what a quadrant is, and I'm going to help you avoid common mistakes. All right, let's get started. How do people know where points go? Today, we're going to make the coordinate plane easy. Section one. What is the coordinate plane? The coordinate plane is a system mathematicians use to locate points. The horizontal line is called the x-axis. The vertical line, up and down, that's the line is called the y-axis. Where they cross, right here, where they

0:47 cross, that's called the origin. The origin is 0,0 because it hasn't gone left or right on the x-axis, and it hasn't gone up or down on the y-axis. It's right where those two intersect. Section two. Ordered pairs. Let's take a look at 3,4. Every point has an address called an ordered pair. Like, where would 3,4 be on this coordinate plane? Now, remember, the x-coordinate always comes first. So, in this case, the three is the x because that comes first. Then, the y-coordinate always comes second, which is the four. So, you have to remember you have to do the x first, going left and right. In

1:34 this case, we're going to go right because it's positive. And then, you do the y-coordinate, which would be four. And that's either up or down. And in this case, it's up because it's positive. I like to think, run before you climb. Move left or right first, and then move up or down. Section three. Positive versus negative. If x is positive, you move right. If X is negative, move left. If Y is positive, move up. If Y is negative, move down. Section four, plotting a point. Let's plot 3,4. Start at the origin, right here at 0,0. We're going to move three units to the right because we do the X first, then we

2:20 move four units up because we do the Y second. And there's our point. That's where 3,4 would live. Let's talk about common mistakes. One of the biggest mistakes students make is moving up first instead of across first. So, they switch around the X and the Y. So, remember, you need to run before you climb. So, move left or right first, then move up and down. So, be careful of that. That is where most of the mistakes happen. Section five, quadrants. Okay, let's take a look at the quadrants. In the top right, we have quadrant one. That's positive, positive, meaning it's going to be a positive X and a positive Y. In our previous example, we

3:05 had 3,4. That was a positive three and a positive four, so we went to the right three and we went up four. That landed us in quadrant one because both the X and the Y were positive. Quadrant two, that's negative, positive. If an ordered pair has an X that's negative and a Y that's positive, it will always land in quadrant two because you're going to go left first for the X and then you go up for the Y. Quadrant three, negative, negative. When the X is negative and the Y is negative, you will always land in quadrant three. Quadrant four, quadrant four is positive, negative. X is positive, Y is negative, and you will land in quadrant four. Quadrants help us describe where points

3:51 are located. All right. Let's do a few examples. Let's find 5, 2. Where would 5, 2 live? Well, keep in mind we're going to go over 5 on the X, up 2 on the Y. 5, 2 would live right there. What quadrant? Yeah, it'll be in quadrant 1. All right. Now let's locate the ordered pair -3, 6. The X is -3, so we need to go to the left three to to -3, and then we're going to go up six on the Y. Yep, we're in quadrant 2 for -3, 6. Okay, now let's do -5, 0. All right, this one's a little tricky because we have a zero for

4:37 one of our X's or Y's. So, -5 in the X means we're going to go to the left five spots, so to -5. Then, because our Y is zero, that means you're not going up or down. You're actually going to stay right on the X axis and put your point right there. This is where -5, 0 would live. All right, what if we flip-flop those? What if we had 0, -5? Since there's a zero in the X now, you wouldn't go left or right at all. You would just stay right at the origin for that part. Then, -5 for Y means you're going to go down five spots on the Y. So, when you put the point right there on the Y axis.

5:23 What about 7, -2? Again, let's do the X first. So, we're going to go over seven, and then we'll do the Y. We'll go down two. That's where 7, -2 would live. If this video was helpful to you, please take a moment, like, subscribe. I don't want you to miss any of my lessons, and if you have a moment, share them with your friends. The more people I can reach and teach about math, the better. Thank you so much. I really appreciate it and we'll see you in the next lesson.