(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Solve each equation using newtons method. The problem I am working on right now is:

[tex] x^{5}+x^{3}+x=1 [/tex]

which is the same as:

[tex] x^{5}+x^{3}+x-1=0 [/tex]

2. Relevant equations

[tex] x_{2} = x_{1}-\frac {f(x)}{f'(x)} [/tex]

with x_{1}being the first guess to what an f(x)=0 would be.

3. The attempt at a solution

So I put the equation into my calculator to graph it and It is very clear from the graph that f(x)=0 on the x>0 side so I choose x_{1}=1 and continue like so:

[tex] x_{2} = 1 - \frac {f(x)}{f'(x)} = 1- \frac {2}{9} = \frac {7}{9} [/tex]

and after 5 iterations I get:

[tex] x_{5} = .6368843716 [/tex]

which looks right to me but when I check the answer in the back of the book it says that it should be -.63688, so just the opposite of what I got. The graph of the equation clearly shows that f(x)=0 on x>0 so did I do something wrong or does the book have another typo?

thanks

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# Homework Help: Newtons Method - A little help

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