f(x)=x(x-1)(x-2)……(x-100)两边取对数得.lnf(x)=lnx+ln(x-1)+ln(x-2)+……+ln(x-1).两边求导数得.f'(x)/f(x)=1/x+1/(x-1)+1/(x-2)+……+1/(x-100).所以.f'(x)=f(x)[1/x+1/(x-1)+1/(x-2)+……+1/(x-100)……（*）.=...