7. Graphing Absolute Value Functions
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Create two tables of values and then plot the graphs on the same coordinate plane.
Graph:
Comparison: See solution.
To graph the functions without going through the entire process of transforming the parent function, we can make two tables of values. Then we only need to plot the ordered pairs that we find.
Let's begin with creating a table of values of function v.
| x | -2|3x+1|+4 | Simplify | v(x) |
|---|---|---|---|
| -2 | -2|3( -2)+1|+4 | -2|-5|+4 | -6 |
| -1/3 | -2|3( -1/3)+1|+4 | -2|0|+4 | 4 |
| 0 | -2|3( 0)+1|+4 | -2|1|+4 | 2 |
| 1 | -2|3( 1)+1|+4 | -2|4|+4 | -4 |
| x | 3|3x+1|-6 | Simplify | w(x) |
|---|---|---|---|
| -1 | 3|3( -1)+1|-6 | 3|-2|-6 | 0 |
| -1/3 | 3|3( -1/3)+1|-6 | 3|0|-6 | -6 |
| 0 | 3|3( 0)+1|-6 | 3|1|-6 | -3 |
| 1 | 3|3( 1)+1|-6 | 3|4|-6 | 6 |
Finally we can take these ordered pairs and plot them on one coordinate plane.
As we can see from the graphs, the function w is a vertical stretch by a factor of 32 and a reflection in the x-axis of the graph of function v.