Things You'll Need:
- Pencil, Paper
- Calculator(?)
- Two Points on a Line
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Step 1
To determine the slope of a line, you'll need to know two points on the line. You might come about these in one of two ways. Sometimes, you are just given two points. Other times, you'll have to find two points from a given graph.
If you already have your two points, skip to Step 3 below.
If you have to find two points from a graph, start here.
Example: Let us suppose you are given the graph that you see in the picture for Step 2 below (click to enlarge the graph). To find the slope of the line, we'll first need to find two points on the line. -
Step 2
Example Graph of a LineYou'll want to select two points whose coordinates are easily determined. I have marked two such points with a red dot (click on the graph to enlarge it). The two marked points are (0,-2) and (2,-1). You may very well find other easily-determined points on this graph that you could use instead.
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Step 3
Formula for SlopeFor this example, our two points are (0,-2) and (2,-1). Plug these points into the formula for slope. The formula for slope is shown as the picture for Step 3. It often helps me to label my points before plugging them into the formula:
(x1,y1) , (x2,y2)
(0 ,-2) , (2 ,-1)
Plug them in the way you've labeled them: -
Step 4
Plug in the NumbersNext, you must simplify. Take your time with it.
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Step 5
SimplifyingAlmost there...
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Step 6
Final AnswerThe answer is: the line has slope one-half or m=1/2.
