Probability is used to calculate the chance that an event will happen.  There are certain rules for probability that help to keep this concept well-defined, including total probability. So,...

Parabolas appear frequently in mathematics.  These graphs have a beautiful symmetry and are useful for solving quadratic equations – but are they functions? So, is a parabola a...

Quadratic equations come up all the time in algebra, as do binomials.  You might be hoping for some shortcuts for factoring quadratic binomials – luckily, there are some that you can...

Expected value (also called mean) is often used in probability and statistics to help describe data sets or to predict outcomes.  However, this raises the question of what types of values we can...

Absolute value appears often in algebra, and it is often used to represent distance.  This raises the questions of how absolute value relates to negative numbers. So, can absolute value be...

Normal distributions are quite common, and they show up everywhere in statistics and in nature.  We are familiar with distributions with positive values (such as height or weight), but what...