I came across an intriguing iterative algorithm for solving a nonlinear equation of the form
ln(f(x))=0
, which differs from the classical Newton's method. This method utilizes a logarithmic difference to calculate the next approximation of the root. A notable feature of this method is its faster convergence compared to the traditional Newton’s method.
The formula for the method is as follows:
$$x_{n+1} = \frac{\ln(f(x + dx)) - \ln(f(x))}{\ln(f(x + dx)) - \ln(f(x)) \cdot \frac{x_n}{x + dx}} \cdot x_n$$
Example:
Using the classical Newton's method, the initial approximation
x0=111.625
leads to
x1=148.474
Using the above method, the initial value
x0=111.625
yields
x1=166.560
which is closer to the exact answer 166.420
Questions:
1. How is this formula derived?
2. Can this method be expected to provide a higher rate of convergence for a broad class of nonlinear functions?
3. What are the possible limitations or drawbacks of this method?