Graphing a line in quadrant 1


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We graph a line whose equation is given, say for example y = 3x. We need at least two points or ordered pairs to graph the line. First we choose some x values. Then we evaluate y = 3x for each value of x.

For example for x = 0, y = 30 = 0; x = 1, y = 31 = 3 and so on. We put the x, y and the ordered pair x,y values as follows.

x y x,y
0 30 = 0 0,0
1 31 = 3 1,3
2 32 = 6 2,6
3 33 = 9 3,9
4 34 = 12 4,12

We see that the ordered pairs lie in the quadrant 1. Joining the points will give the graph of the line in quadrant 1.

Graphing a line in quadrant 1

Graph the line in the quadrant 1, whose equation is given below.

2x – y = 3

Solution

Step 1:

Given equation 2x – y = 3; for y = 0, x = 3/2; for x = 2, y = 22–3 = 4–3 = 1. So two ordered pairs are 3/2,0 2,1

Step 2:

Plotting the points and joining with a line we get

Graphing a line in quadrant 1 Example1 Step2

Graph the line in the quadrant 1, whose equation is given below.

x + 3y = 1

Solution

Step 1:

Given equation x + 3y = 1; for y = 0, x = 1; For x = 0, y = 1/3. So two ordered pairs are 1,0 and 0,1/3

Step 2:

Plotting the points and joining with a line we get

Graphing a line in quadrant 1 Example2 Step2