(disregard "part a" mention) According to the solution all terms in the Lebniz formula but one cancel out. Could someone please illustrate this?
Thanks in advance :)
Oh I understand now:
Because $u^\left(p\right)=p!$ and $v^\left(q\right)=q!$,
whenever there is a term with a derivative higher than p (>p), you are actually differentiating p factorial (when p+1) or 0 (when $>p+1$). Whenever there is a term with a derivative lower than p, you are differentiating q factorial (when p-1) or 0 (when $<p-1$).
So there is only one instance where you are not differentiating a constant.