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If
you can graph a straight line, you can graph an
inequality!
Graphing an inequality starts by graphing the
corresponding straight line. After
graphing the line, there
are only two additional steps to remember.
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1.
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Choose a point
not
on the line and see if
it makes the inequality true. If the inequality is
true, you will shade THAT side of the line -- thus shading
OVER the point. If it is false, you will shade the
OTHER side of the line -- not shading OVER the point. |
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2. |
If the inequality is LESS THAN OR
EQUAL TO or GREATER THAN OR EQUAL TO, the line is drawn as
a solid line. If the inequality is simply LESS THAN
or GREATER THAN, the line is drawn as a dashed line. |
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Graphing
an Inequality |
1. Solve the equation
for y (if necessary).
2. Graph the equation as if it contained an = sign.
3. Draw the line solid if the inequality is 
or 
4. Draw the line dashed if the inequality is <
or >
5. Pick a point
not on the
line to use as a test point.
The point (0,0) is a good test
point if it is not on
the line.
6. If the point makes the inequality true, shade
that
side of the line. If the point does not make
the
inequality true, shade the opposite side of the line. |
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Graph the
following inequality
y
3x - 1
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Graph the inequality
y
3x - 1
1.
Graph the line y = 3x - 1.
2. Pick a test point.
(0,0) was used.
3. The test point is false in the
inequality
0
3(0) - 1
0 -1
false
4. Since the test was false, do
not shade OVER the point (0,0) -- shade the
opposite side of the line.
5. The line, itself, is SOLID because this problem is
"less than or EQUAL TO." |
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