Theorem: QF.COMP: For
any quadratic function,$f$,
there are numbers $A, h$, and $k$, so that $f$
can be expressed as a composition of the core quadratic
function, $q(x) =x^2$, with core linear
functions:
$f(x) = (f_{+k} \circ f_{*A} \circ q\circ
f_{-h} )(x)= A (x-h)^2 + k$
where $f_{+k}(u)=u+k $, $f_{-h}(u)=u-h $, and $
f_{*A}(x)=Ax$.