Question

determine the domain on which the following function is decreasing.

Explanation:

Step1: Recall decreasing - function definition

A function \(y = f(x)\) is decreasing when as \(x\) increases, \(y\) decreases.

Step2: Analyze the graph

Looking at the graph, we see that as \(x\) moves from negative - infinity to the \(x\) - coordinate of the vertex, the \(y\) - values of the function are decreasing.

Answer:

\((-\infty, a)\) (where \(a\) is the \(x\) - coordinate of the vertex of the parabola)