BOB-muddiest point

So far my muddiest point in this class has been understanding domain and range. I sometimes confuse the different methods for finding them, such as when to set them equal to zero. I especially get confused when there is a radical over a radical and the other hard ones similar to that. It helped a lot though when I realized for this unit  we only had to worry about having a domain are radical and rational functions. This helped to clear up my confusion a little. It is also confusing to me when we are finding the inverse when there are two "X"s or two "Y"s. I am still working on understanding that.