I feel really dumb for not knowing this problem. I'm trying to study for my precalc final and I stumbled upon this problem. I gives me a graph: And asks me to find: (f o g)(2) (g o f)(2) (f o f)(2) (g o g)(2) (f + g)(2) (f / g)(2) I know how to compute nested functions as well as function addition/division....just not when I'm given a graph :/ . Any help is greatly appreciated!
Well, I'm a bit rusty on my math, but I believe (f o g)(2) is the same as f(g(2)), right? If so, then in order to find the answer, you'd have to first use the graph to find g(2), which is 0. That gives you f(0), which isn't defined on the graph (So I guess I'm either wrong, the answer just doesn't exist, or the line doesn't have a domain as shown in the graph). For the other ones, you'll just have to move the functions around so that you'd find f(2) first and then use that value as the input for function g, or input 2 into g and use that output as the input for g, etc.
Yep, Victor's got it---you look at the graph to determine the output of the function at the value in question so for addition you just do f(2)+g(2)=1+0=1
Thanks a lot! We use Webwork, so all of our homework is online; I just did what you suggested and it worked ^__^ .
