This week in Precalculus 11, we started the Graphing Inequalities & Systems of Equations unit. We first learned about solving quadratic inequalities in one variable.

quadratic inequality: an expression with degree 2 that is not equal to 0

It can be written in general form as a + bx + c >/</≥/≤ 0

To solve a quadratic inequality, we first rearrange the inequality to general form. We then write and solve its corresponding quadratic equation. We label a number line with the roots. We then test a number from each interval by substituting it into the original inequality.

Example:

This was new to me, as I had learned how to solve linear inequalities, but not quadratic inequalities.