This week in Precalculus 11, we started the Analyzing Quadratic Functions unit. We first learned about the properties of a quadratic function.

**quadratic function: **function that can be written in general form

**general form: **y = a + bx + c, where a ≠ 0

**parabola**: the curve of a quadratic function’s graph

**vertex: **a parabola’s highest (minimum) or lowest (maximum) point (if the coefficient of is positive, the vertex opens up. If it is negative, the vertex opens down)

**axis of symmetry:** intersects parabola at its vertex

**domain: **all possible x values

**range:** all possible y values

**x-intercepts: **where the parabola touches the x axis, the roots of the quadratic equation

**y-intercepts: **where the parabola touches the y axis.

Example: y = 2 + 8x + 6

x: -5, -4, -3, -2, -1, 0

y: 16, 6, 0, -2, 0, 6

vertex: (-2, -2) minimum/opens up

x-intercept: (-1, 0) & (-3, 0)

y-intercept: (0, 6)

axis of symmetry: x = -2

D: {x∈R}

R: {y ≥ -2}

I had not learned about many of these terms before and found it interesting that you could find so much information from the vertex.