http://www.freemathvideos.com In this math video tutorial I describe how to find the domain of a function by determining when the bottom of a rational function is zero and when the root is negative. I also might look at the graph and determine the intervals for the domain of the function. For a rational expression we set the bottom of the rational expression to zero and solve for x. For a function with an even root we set the radicand greater than or equal to zero and solve for x. Less