1. The problem statement, all variables and given/known data I have to understand this to understand my homework. What is the difference between these two function compositions? 2. Relevant equations f at g(a) f o g at a 3. The attempt at a solution Let's make f(a) = a^2 and g(a) = 3a. It seems that "f at g(a)" means f(g(a)) which equals (3a)^2. And it also seems like "f o g at a" means f(g(a)) which equals (3a)^2.