How to use it
- Evaluate the inner function first.
- Substitute that result into the outer function.
- Track domain restrictions.
See it in action
f(x)=x+1, g(x)=2x: f(g(3))=f(6)=7.
How to verify it
Direct formula f(g(x))=2x+1 gives 7 at x=3.
Think of Function Composition as a Pipeline
In f(g(x)), the output of g becomes the input of f.