Identify a1 and r for the sum of the geometric series.

−4, 8, −16, 32,…

an = -4(-2)^n-1

Step-by-step explanation:

Domain: All real numbers, or (-∞,∞) depending on how you want to write it.

Range: [-4, ∞)

Vertex: (-2, -4)

Axis of symmetry: x = -2

Interval of increase: (-2, ∞)

Interval of decrease: (-∞, -2)

Y-int: (0, 0)

X-int/Zero/Solution(s): (-4, 0) and (0, 0)

For a polynomial function like this, which is a quadratic function, the domain is always negative infinity to positive infinity, or all real numbers.

The range is the lowest y-value to the highest y-value. The lowest y-value for this is at the vertex, but the function has no upper limit for the y-value.

The vertex is the point that you can very clearly see is at the tip of the graph.

Axis of symmetry is the vertical line that splits the graph in half at the vertex.

Interval of increase is the interval x values for which the function is increasing. The function increases to the right of the vertex.

Interval of decrease is to the left of the vertex.

The y-intercept is clearly (0, 0), where the graph intersects the y-axis.

The x-intercepts are also clear, since you can see where the graph intersects the x-axis.