Question 1201001
f(x) = x^2
g(x) = x+2


f(g(x)) = (x+2)^2
g(f(x)) = x^2+2


f(3) = 3^2 = 9
g(f(3)) = 9+2 = 11


g(3) = 5
f(g(3)) = 5^2 = 25


what you are doing wih the composite function, you are replacing x with f(x)


example 1:


g(x) = x + 2
f(x) = x^2
f(g(x)) = (x+2)^2
what you did was replace the x in f(x) with g(x).


example 2:


f(x) = x^2
g(x) = x + 2
g(f(x)) = x^2 + 2
what you did was replace the x in g(x) with f(x)


here's a reference.


<a href = "https://www.mathsisfun.com/sets/functions-composition.html" target = "_blank">https://www.mathsisfun.com/sets/functions-composition.html</a>
if you have any questions about how this is done, let me know and i'll explain further as best i can.
theo