Use a calculator to graph the functions. Draw a simple graph of the function and then analyze the equation to determine what its domain would be. Use the trace button on the calculator to determine if a x-value is included or not included. If it is included, there will be a y-value on the calculator. If it is not included, the y-value will be blank on the calculator. After a few of the same type of equations, you should be able to determine what the implicit domain is without looking in the calculator!