How to find the domain of a rational equation

The video tutorial explains how to determine the domain of a function, focusing on the concept of implied domain and restrictions due to denominators. It emphasizes that the domain is all real numbers unless the denominator equals zero, which is not allowed. The tutorial guides viewers on solving for the domain by setting the denominator to zero and using interval notation to express the domain, highlighting the use of union to connect intervals.

What does the interval notation for the domain look like when there is a restriction at -3?

Explain the concept of union in the context of domain restrictions.