Beginning & Intermediate Algebra
f∘g is the function f(g(x)); g is the inside function and f is the outside function.
f∘g equals f(x)+g(x) and the inside function is whichever one appears on the right in the expression, but both are considered outside in different contexts.
f∘g is the product f(x)·g(x); there is no inside or outside function because multiplication is symmetric and composition isn't involved.
f∘g is the function g(f(x)); f is the inside function and g is the outside function, which is the usual convention when composing functions.