## Thomas' Calculus 13th Edition

$P'(x)=na_nx^{n-1}+(n-1)a_{n-1}x^{n-2}+...+2a_2x+a_1$,
Given $P(x)=a_nx^n+a_{n-1}x^{n-1}+...+a_2x^2+a_1x+a_0$, $a_n\ne0$, using the Power Rule, we have $P'(x)=na_nx^{n-1}+(n-1)a_{n-1}x^{n-2}+...+2a_2x+a_1$,