| Piecewise-defined functions |
-- Section 3.3 -- |
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| Graph the following: |
| There is one function that has 2 different parts. | ||
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Solve |
Step |
Check |
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Part 1: y = f(x) = 3 |
when x < -2 | |
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Horizontal line y =
-3
The open circle denotes that -2 is not Click here for Lines Tutorial. |
f(-10) = -3 since -10 <
-2
f(-6) = -3 since -6 < -2 f(-1.9) = -3 since -1.9 < -2 f(-2) = -2 since -2 > -2 |
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Part 2: y = f(x) = x |
when x > -2 | |
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Linear function y =
f(x) = x
The closed circle denotes that -2 is not Click here for Lines Tutorial.
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f(-2) = -2 since -2 >
-2
f(0) = 0 since 0 > -2 f(2) = 2 since 2 > -2 f(4) = 4 since 4 > -2 |
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Put both parts together... |
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It is beautiful! | |
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| Graph the following: |
![]() |
[Solution] |
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Graph the following:![]() |
| There is one function that has 3 different parts. | ||
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Solve |
Step |
Check |
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Part 1: y = f(x) = -x - 2 |
when x < -2 | |
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Linear function y =
f(x) =
-x - 2
The open circle denotes that -2 is not included Click here for Lines Tutorial. |
f(-5) = -(-5) -
2 = 3 since -5 <
-2
f(-4) = -(-4) - 2 = 2 since -4 < -2 f(-3) = -(-3) - 2 = 1since -1.9 < -2 |
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Part 2: y = f(x) = 4 - x2 |
when -2 < x < 2 | |
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Quadratic function y =
f(x) = x
The closed circle denotes that -2 and 2 is included since -2 < x < 2 Click here for Quadratic Tutorial.
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f(-2) = 4 - (-2)2 =
4 - 4 = 0
since -2 < -2 <
2 f(-1) = 4 - (-1)2 = 4 - 1 = 3 since -2 < -1 < 2 f(0) = 4 - (0)2 = 4 - 0 = 4 since -2 < 0 < 2 f(1) = 4 - (1)2 = 4 - 1 = 3 since -2 < 1 < 2 f(2) = 4 - (2)2 = 4 - 4 = 0 since -2 < 2 < 2 |
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Part 3: y = f(x) = x - 2 |
when x > 2 | |
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Linear function y =
f(x) = x
- 2
The open circle denotes that 2 is not Click here for Lines Tutorial. |
f(3) = 3 - 2 = 1 since
3 > 2 f(4) = 4 - 2 = 2 since 4 > 2 f(5) = 5 - 2 = 3since 5 > 2 |
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Put both parts together... |
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It is beautiful!
Notice the open circles and closed circles overlap. |
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Graph the following: |
![]() |
[Solution] |
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Tutorials and Applets by
Joe McDonald
Community College of Southern Nevada