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Graph functions ` y= 1/4x - 2` and `y = -2x` . Thank You
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High School Teacher
Since the equation is in slope-intercept form, use the y-intercept and the slope to graph it.
The y-intercept of this equation is (0,-2). And its slope is 1/4.
Since the slope is `1/4` , to get the next point, move (0,-2) one unit up and 4 units to the right. Hence, the next point is (4, -1). And to get the point next to this, move (4,-1) one unit up and 4 units to the right. So, the next point is (8,0).
Then, connect these three points and extend the line on both ends.
Hence, the graph of `y=1/4x-2` is the blue line below.
Again, this equation is in slope-intercept form. So to graph this, use its y-intercept and slope.
The y-intercept of this equation is (0,0) and its slope is -2. For clarity, express the slope as a fraction. Its fraction form is `-2/1` .
So, plot the point (0,0). Then, refer to the slope `-2/1` to determine the next point.
To get the next point, move (0,0) two units down and one unit to the right. Hence, the next point is (1,-2). To get the point next to this, move (1,-2) two units down and one unit to the right. Hence, the next point is (2, -4).
After plotting the three points, connect them and extend the line on both ends.
Hence, the graph of `y=-2x` is the red line below.
Posted by mjripalda on September 19, 2013 at 2:03 AM (Answer #1)
High School Teacher
Both equations are written in slope intercept form: `y = mx + b.`
In the equation `y = 1/4x - 2, ` `1/4` , is the slope and -2 is the y-intercept.
Plot (-2) on the y-axis and use slope (rate of change) to find next point. Since slope is 1/4, from the y-intercept, count up 1, right 4 and graph line. (See black line on graph)
In the equation `y = -2x` , -2 is the slope and 0 is y-intercept. Plot y-intercept, then count down 2 right 1 for slope. Draw line. (See red line on graph).See graphs below.
Posted by baxthum8 on September 19, 2013 at 11:54 AM (Answer #2)
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