1. Graphing Quadratic Functions
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Make a table of values and connect the points with a parabola.
Graph:
Domain: { all real numbers }
Range: { y | y≥ - 5 }
We want to graph the given quadratic function.
y=3x^2-6x-2
To do so, we will first make a table of values.
| x | 3x^2-6x-2 | y=3x^2-6x-2 |
|---|---|---|
| - 1 | 3( - 1)^2-6( - 1)-2 | 7 |
| 0 | 3( 0)^2-6( 0)-2 | - 2 |
| 1 | 3( 1)^2-6( 1)-2 | - 5 |
| 2 | 3( 2)^2-6( 2)-2 | - 2 |
| 3 | 3( 3)^2-6( 3)-2 | 7 |
Now, let's plot the obtained points and connect them with a parabola.
We can see above that the x-variable can take any value. Conversely, the y-variable only takes values greater than or equal to - 5. Using this information, we can write the domain and range of the function. Domain:& { all real numbers } Range:& { y | y≥ - 5 }