Solving Newton's Method for f(x) = 0: Step-by-Step

EL ALEM
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Homework Statement


Nother Q for today:
Let f(x)= (1/x)^x - x
(a)show that f(x)=0 has a solution
(b)show that there is only one solution to f(x)=0
(c)use Newton's Method to find the second approximation x2 of the solution to f(x) =
0 using the initial approximation x1 = 1/2


Homework Equations





The Attempt at a Solution


I know how to do part C just need a little kick in the right direction for the first part.

(1/x)^x - x = 0
(1/x)^x = x
xln(1/x) = lnx
 
Last edited:
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EL ALEM said:
x \log(1/x) = \log(x)

Remember what \log(a/b) equals to? Break the pieces out.
 
How about the simple fact that 1 to any power is 1?
 
I already got it, it was late and I wasn't thinking straight, thanks for the replies though.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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