Exploring Quadratic Functions — Visual Lab
The parabola is the first curve. Move the controls and watch one quadratic appear three ways at once — and see what the vertex, the axis, and the roots really mean.
This is the Module 2 lab bench. Every quadratic can be written three equivalent ways — standard \(ax^2+bx+c\), vertex \(a(x-h)^2+k\), and factored \(a(x-r_1)(x-r_2)\). They look different, but they describe the same parabola. Drag \(a\), \(h\), and \(k\); the graph, the vertex, the axis of symmetry, the roots, and all three equations update together — and when the curve lifts off the x-axis, watch the roots turn complex.
The Quadratic Forms Explorer
Three sliders. One parabola. Three equivalent equations — standard, vertex, and factored — all kept in sync.
How to Read the Lab
Two minutes of orientation, then four moves to try. Everything updates live as you drag.
What you're seeing
- The violet curve is your parabola \(f(x)=a(x-h)^2+k\). The a slider stretches it and flips it open-up or open-down; h slides the vertex left and right; k slides it up and down.
- The filled violet dot is the vertex \((h,\,k)\) — the turning point — and the dashed vertical line is the axis of symmetry \(x = h\).
- The amber dots are the roots (x-intercepts): where the parabola crosses the x-axis. If the curve never touches the axis, there are no real roots and the dots disappear.
- The three cards below show the standard, vertex, and factored forms of the very same function — click a card to spotlight it.
- The readout names the vertex, axis, direction of opening, min/max, y-intercept, and the discriminant \(b^2-4ac\) that decides how many real roots there are.
Try this
- Leave \(a=1\) and drag k up above \(0\). The vertex lifts off the x-axis, the amber roots vanish, and the factored card warns the roots are now complex — that's a negative discriminant.
- Set \(k=0\) exactly. The two roots collapse into one repeated root at the vertex — a perfect square. Read it off the factored card.
- Hold \(h\) and \(k\) fixed and flip a from positive to negative. The parabola opens the other way and the vertex switches from a minimum to a maximum.
- Move only h. Watch the axis of symmetry \(x=h\) track the vertex, and notice the standard form's middle term \(b=-2ah\) change while the vertex form just shifts.
Key Vocabulary & Standards
The words that unlock Module 2, and the TEKS this lab is built to teach.
Where to Go Next
Back to the course, or deeper into the plan for Module 2.
Instructor: Dr. Goodluck Ijezie-Desbois, PharmD · Beta Academy · Room: TBA
This lab is built on the TEA Bluebonnet Learning — Secondary Mathematics open curriculum,
licensed CC BY-NC 4.0. Non-commercial classroom use.