WEBVTT
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Alright, what I'd like to do now is show you guys how to plot a graph using a table on x and y intercepts.
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So, so far we've talked about just how to find the x and y intercepts.
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And what we've found out is to find the x and y intercepts, what you need to do is you need to find out the x intercepts would
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equal zero when it crosses the y axis and the x intercepts is when a graph crosses the x axis.
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So, if I was going to say graph a line and I want you to know how to graph using a table, what I'm going to do is I'm going to have to plot these points.
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So, the first thing I'm going to go look at is I'm going to go plot these points.
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So, remember, a coordinate, on our coordinate grid we have plots of, given with your x and y, where your x refers to where to plot the point on the x axis.
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And your y coordinate tells you where to plot your point on your y axis.
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So, if I'm telling you to go and plot your point at negative two, negative three, I go to the left, negative two, and I go on the y axis, negative three, one, two, three.
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And I just make a nice little point there.
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Then, I plot the point negative one, negative one.
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So, I go to the left, negative one, on the x axis, and I go down, negative one, on the y axis.
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And the next point I'm going to go is zero on the x axis, is just going to be right there, and then up one.
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Which would be right there.
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Then I go over one, up three.
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So, over one, up three.
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And then my next point is going to be two four.
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So, I go over two, up four, one, two, three, four.
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That does not look great at all.
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Oh, that should be five.
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No wonder.
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There you go.
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I've got one of my own other equations.
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Now, I can go and plot the points still by connecting them.
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I have my equation for my graph.
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Now, let's say I was going to go and graph another line.
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If I was going to go and find out what the x and y intercepts for this line is, we know that the x intercept is when y equals zero.
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And my y intercept is when x equals zero.
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So, therefore, define my x and y intercept.
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If I'm going to plot this graph, I'm going to put zero in for y.
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So, x equals, sorry, x plus two times zero equals four.
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My y intercept is x equals zero.
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So, zero plus two y equals four.
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My x intercept ends up equaling four.
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My y intercept, when I divide by two, two y equals four.
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Divide by two, y equals two.
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So, therefore, to put these as a coordinate point, this is four comma zero.
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And this is zero comma two.
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Because x is zero and y is two.
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Over here, I have y zero and x is four.
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So, if I'm going to graph down this equation, I'd go to my x intercept, which is four zero, one, two, three, four, and make it plot.
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And then I'd go to my next point, when y is zero, or y is two, and I go there, and then I connect these two points.
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And that's how you graph your second line.
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So, there's two ways I have showed you guys how to graph in line.
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One using a table, and one using finding the x and y intercepts.