Expert: Sherry Wallin - 10/9/2009

Question
Hi

I'm using this computer system called ALEKS, and one topic is frustrating me to no end.

As you see, it's the advanced composition of functions, i.e (f 0 g)(x)

I know how to set it up and everything, but I also need to find the domain of (f 0 g)(x) and I just don't understand how.  I've been trying for the past 2 hours and the explaination on ALEKS is poor.  Can you help me at all?  

Thanks

Answer
Hi Aimee you need to give me an example to use to help you. Basically (fog)(x)=f(g(x)) which means that the domain will be the range of g(x).Think of it this way. you are finding g(x) and getting a result and then using those results to find f(x). When you find a function it's result is the range. So you find g(x) using the domain of x and then you find f(x) using the domain which is the range of the inside function g(x). Does this help you understand better?

Math Prof