If the vertex (h,k) and the coefficient a of x^2 are known, you can write the equation of the parabola in vertex form.
1. Draw a vertex point.
• Select and then click in the pad to get your vertex A.
2. Click on the "Vertex" button.
3. Click on the "Draw Parabola" button.
Now - let's have some fun before calculating .
4. Change the coefficient a!
How? What does a do?
5. Draw the axis of symmetry through the vertex.
6. Change the coefficient a again.
What doesn't move?
7. Move the vertex A.
How? What controls the axis of symmetry?
Use the or and click and drag the blue point to the left of the slider to move your parabola anywhere on the graph!
Okay - boring bit coming up.
IMPORTANT: Click on the "Vertex" button!
Vertex: (x, y) \quad
If the parabolas match then your answer is correct!