# Math Vocabulary

### Quadratics Ch 9

## Quadratic

## Vertex

## Axis of Symmetry

The two sides of a graph on either side of the

**axis of symmetry**look like mirror images of each other. Example: This is a graph of the parabola y = x2 – 4x + 2 together with its**axis of symmetry**x = 2. The**axis of symmetry**is the red vertical line.

## Maximum/Minimum Value

To see whether it is a maximum or a minimum, in this case we can simply look at the graph. f(x) is a parabola, and we can see that the turning point is a minimum. By finding the value of x where the derivative is

**0**, then, we have discovered that the vertex of the parabola is at (3, −4).

## Term

## First Difference

The

**first**-**difference**(FD) estimator is an approach used to address the problem of omitted variables in econometrics and statistics with panel data. The estimator is obtained by running a pooled OLS estimation for a regression of on .

## Second Differences

**defined**by a quadratic formula, the

**second differences**will be constant and equal to twice the number of n2 . For example,