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Use the vertex form. Where is the axis of symmetry of a parabola located?
Example Equation: y = 12(x-3)^2+2
Axis of Symmetry: x=3
Example Points: (1,4) and (5,4)
The parent function for a quadratic function is y=x^2, and its graph is a parabola.
Any quadratic equation can be written in vertex form. The vertex form represents a transformation of the parent function.
y = a(x- h)^2 + k
The axis of symmetry for a parabola is the vertical line passing through the vertex. In this case, it is represented by the line x= 3. Notice that this line divides the parabola in two halves in such a way that one is the mirror image of the other.
Finally, we can locate two points lying on the parabola by looking at the graph. However, if we did not have the graph at hand, we could do this by evaluating the quadratic function for two different arbitrary values of x.
| x | 1/2(x-3)^2+2 | y |
|---|---|---|
| 1 | 1/2( 1-3)^2+2 | 4 |
| 5 | 1/2( 5-3)^2+2 | 4 |
Notice that we could have used any value for a to get our equation. Furthermore, we could have evaluated the function at any two x values to get the points. Therefore, there are infinitely many possible solutions fulfilling this exercise's requirements. This is just one example solution.