设f(x)=√（2-x),g(x)=√x,h(x)=2-x那么：f(x)=g[h(x)],g'(x)=x^(1/2)=1/2x^(-1/2),h'(x)=-1根据求导法则：f'(x)={g(h)}'(x)=g'(h(x))h'(x)所以√（2-x)的导数=1/2(2-x)^(-1/2)(-1)=-1/2(2-x)^(-1/2)...