Quadratics Ch 9
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.
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).
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 .