نکته: اگر $f\left( x \right)={{u}^{n}}$ باشد می‌توان گفت: $f\left( x \right)={{u}^{n}}\to {f}'\left( x \right)=n{u}'{{u}^{n-1}}$ $\begin{align}  & u={{x}^{4}}-3{{x}^{2}}+1\,\,\,\,\,\,,\,\,\,\,\,\,{u}'=4{{x}^{3}}-6x\,\,\,\,\,\,,\,\,\,\,\,\,\,\,n=4 \\  & {f}'\left( x \right)=n{u}'{{u}^{n-1}}=4\left( 4{{x}^{3}}-6x \right){{\left( {{x}^{4}}-3{{x}^{2}}+1 \right)}^{3}} \\ \end{align}$