How do you graph y=|x+5|?

1 Answer
Mar 6, 2016

See the explanation about method.

Explanation:

Build a table for y=x+5 but make all values for y positive

Use this table to plot points. However; this is a plot involving two straight lines that make a V shape. So, in theory you only need 3 points.

The y-intercept is at x=0 so y=|0+5|=5

Thus the first point P1(x1,y1)(0,5)

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The x-intercept is at y=0

y=0=x+5 0=x+5

Add x to both sides 0+x=x+x+5 x=0+5

Thus the second point P2 (x2,y2) (5,0)
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The third point will be a reflection of the first point about the axis of symmetry of x=5 thus completing the V shape

So the x-coordinate will be x2+(x2x1)=5+5=10
The y coordinate will be the same as y1

Thus the third point P3 (x3,y3) (10,5)

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Both of these plotted lines will be extended upwards to the edge of the graph.
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