Question

21 what is the interval of increase for the function represented by the graph?

Explanation:

Step1: Identify the vertex

The graph is a parabola with vertex at $x=3$.

Step2: Determine increasing interval

For a right-opening upward parabola, the function increases when $x$ is greater than the vertex's $x$-value. So the interval is $x > 3$, or in interval notation $(3, \infty)$.

Answer:

The interval of increase is $(3, \infty)$ (or $x > 3$)