Mathematics for IGCSE & O level - Functions (Section 1 - No. 36)
What does g(f(x)) mean?
Multiply g(x) by f(x).
Substitute f(x) into g(x).
Substitute g(x) into f(x).
Add g(x) and f(x).
Paliwanag
This indicates a composite function where you substitute the value of f(x) into the function g.