# Math Help - Fifth degree equation

1. ## Fifth degree equation

How to use newton-rhapson to solve like these equation ?

(1) x^5+15x+12=0
(2)x^5+330x-4170=0

2. ## Re: Fifth degree equation

Choose a suitable starting value \displaystyle \begin{align*} x_0 \end{align*}, then

\displaystyle \begin{align*} x_{n + 1} = x_n - \frac{f(x_n)}{f'(x_n)} \end{align*}

3. ## Re: Fifth degree equation

For no.1 Expression is negative when x=-1 and positive when x=0 so choose a starting value between -1 and 0