Friday, November 30, 2018

calculus - Find the following finite sum


$f(x)=c_{2014}x^{2014}+c_{2013}x^{2013}+\dots+c_1x+c_0$ has 2014 roots $a_1,\dots,a_{2014}$ and $g(x)=c_{2014}x^{2013}+c_{2013}x^{2012}+\dots+c_1
$
. Given that $c_{2014}=2014$ and $f '(x)$ is the derivative of $f(x)$, find the sum $\sum_{n=1}^{2014}\frac{g(a_n)}{f '(a_n)}$.





$f(x)=2014(x-a_1)(x-a_2)\dots (x-a_{2014})$



$f'(x)=2014^2x^{2013}+2013\cdot c_{2013}x^{2012}+\dots+c_1$



is there any relation between $f(a_n)$, $g(a_n)$ and $f'(a_n)$ or do you need different approach to solve?
Edit
As Gerry suggested
now I have

$\frac{-c_0}{2014}\left(\frac1{a_1\prod_{i\neq 1} (a_1-a_i)}+\frac1{a_2\prod_{i\neq 2} (a_2-a_i)}+\dots+\frac1{a_{2014}\prod_{i\neq2014} (a_{2014}-a_i)}\right)$



Would be helpful if someone tell me what to do next

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