It only takes the denominator to be zero to make an expression undefined. A video resource makes the connection of undefined fractions to rational expressions. It points out that to determine when a rational expression is undefined, you just need to set the denominator to zero and solve. The examples using linear and simple quadratic denominators help cement the concept for learners.
- Have the class graph the functions defined by the expression to see what happens at the undefined spot
- Provide additional problems so pupils can practice the concept
- The class should be familiar with solving linear and quadratic equations
- The video is specifically designed for the Common Core standard
- The presenter takes a look at the concept in two different ways