1. **Problem Statement:** Determine the domain on which the function $y = f(x)$, a downward-opening parabola with vertex near $(-3,4)$, is increasing. 2. **Key Concept:** For a parabola $y = ax^2 + bx + c$ with $a < 0$ (opens downward), the function increases on the interval to the left of the vertex and decreases to the right. 3. **Vertex Form and Increasing Interval:** The vertex is at $x = -3$. Since the parabola opens downward, the function is increasing on the domain $$(-\infty, -3)$$. 4. **Conclusion:** The function is increasing for all $x$ such that $$x < -3$$. This matches the graph description where the function increases from about $-10$ up to $-3$ and then decreases afterwards.