Question: User: y = a*x^2 + b*x + c
1. **State the problem:** We are given a quadratic function $$y = a x^2 + b x + c$$ where $$a$$, $$b$$, and $$c$$ are constants.
2. **Formula and explanation:** This is the general form of a quadratic equation. The graph of this function is a parabola.
3. **Important rules:**
- If $$a > 0$$, the parabola opens upwards.
- If $$a < 0$$, the parabola opens downwards.
- The vertex of the parabola is at $$x = -\frac{b}{2a}$$.
- The axis of symmetry is the vertical line $$x = -\frac{b}{2a}$$.
4. **Intermediate work:**
- To find the vertex, substitute $$x = -\frac{b}{2a}$$ into the equation:
$$y = a \left(-\frac{b}{2a}\right)^2 + b \left(-\frac{b}{2a}\right) + c$$
- Simplify:
$$y = a \frac{b^2}{4a^2} - \frac{b^2}{2a} + c = \frac{b^2}{4a} - \frac{b^2}{2a} + c$$
- Combine terms:
$$y = -\frac{b^2}{4a} + c$$
5. **Final vertex coordinates:**
$$\left(-\frac{b}{2a}, c - \frac{b^2}{4a}\right)$$
This vertex represents the maximum or minimum point of the parabola depending on the sign of $$a$$.
6. **Summary:** The quadratic function $$y = a x^2 + b x + c$$ describes a parabola with vertex at $$\left(-\frac{b}{2a}, c - \frac{b^2}{4a}\right)$$ and axis of symmetry $$x = -\frac{b}{2a}$$.