Working Formula for finding Domain (Df)


1. Solve y in terms of x. ( In some cases this step is not  required in case y is given in terms of x).


2. Find those values of x for which y is well-defined and real.


3. The set of the values of x for which y is well defined and real is domain of f. i.e. Df


Working Formula for finding Range (Rf)

For Range we repeat steps 1 and 2 of Domain with the roles of x and y interchanged.

Thus if X= R, Y=R then Domain of f i.e., Df = {x E R: f(x) E R} and R={f(x): x E Df}