1. **Problem:** Determine the rule, in general form, of a quadratic function with vertex $V(1, -8)$ and one zero at $x=3$.
2. **Recall the vertex form of a quadratic function:**
$$f(x) = a(x - h)^2 + k$$
where $(h, k)$ is the vertex.
3. **Substitute the vertex:**
$$f(x) = a(x - 1)^2 - 8$$
4. **Use the zero at $x=3$ to find $a$:**
Since $f(3) = 0$, substitute $x=3$:
$$0 = a(3 - 1)^2 - 8$$
$$0 = a(2)^2 - 8$$
$$0 = 4a - 8$$
5. **Solve for $a$:**
$$4a = 8$$
$$a = \frac{8}{4} = 2$$
6. **Write the function with $a=2$:**
$$f(x) = 2(x - 1)^2 - 8$$
7. **Expand to general form:**
$$f(x) = 2(x^2 - 2x + 1) - 8$$
$$= 2x^2 - 4x + 2 - 8$$
$$= 2x^2 - 4x - 6$$
**Final answer:**
$$\boxed{f(x) = 2x^2 - 4x - 6}$$
Vertex Zero D41E23
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