Question

what does the "composites of a function" mean?

Answer 1

peeling an onion

Answer 2

\[f\circ g(x)=f(g(x))\]
for example if
\[f(x)=x^2+x\] and
\[g(x)=x-4\] then
\[f\circ g(x)=f(x-4)=(x-4)^2+(x-4)\]