Find the Decreasing Interval of a Parabola with Vertex at x = -6

To solve this problem, we'll analyze the behavior of a parabola based on its vertex:

• Step 1: Identify the vertex. We are given that the vertex is at $x = -6$.
• Step 2: Understand that a standard upward-opening parabola decreases to the left of its vertex. Thus, it decreases on the interval $(-\infty, -6)$.
• Step 3: Since we need the interval where it is decreasing: Given the parabola decreases on $(-\infty, -6)$, the function is increasing on $x > -6$.

Therefore, for a standard parabola, the function is decreasing on the interval $x < -6$ which means:

Therefore, the solution to the problem is $x > -6$.