# Vocab Chapter 9

## Parabola

1. A symmetrical open plane curve formed by the intersection of a cone with a plane parallel to its side. The path of a projectile under the influence of gravity ideally follows a curve of this shape.

Involving the second and no higher power of an unknown quantity or variable.

## Vertex

1. Each angular point of a polygon, polyhedron, or other figure.

## Axis of symmetry

A line of symmetry for a graph. The two sides of a graph on either side of the axis of symmetry look like mirror images of each other.

## Maximum value

The maximum value of a quadratic function f(x) = ax2 + bx + c where a < 0, is the y- coordinate of the vertex.

Example The maximum of {14, 4, 16, 12} is 16.

## Minimum value

The minimum value of a quadratic function f(x) = ax2 + bx + c where a > 0, is the y- coordinate of the vertex.

Example The minimum of {14, 4, 16, 12} is 4.

## Terms

1. Each of the quantities in a ratio, series, or mathematical expression.

## First differences

First Differences So basically, in a real question, you would know your x variable and y and then, what you do to find a first difference is subtract. First you find all the numbers on the 'y' side and subtract by subtracting the bottom number below the first number in the 'y' column.

## Second differences

Calculate the first 6 terms of the sequence defined by the quadratic formula, then simply to four terms then 3 terms.

## zeros(roots)

Where a function equals the value zero (0).

Example: -2 and 2 are the zeros of the function x2 - 4