Problem

Use Newton's method to find an approximate solution of $\ln (x)=5-x$. Start with $x_{0}=8$ and find $x_{2}$

Answer

Expert–verified
Hide Steps
Answer

Final Answer: \(x_{2} = \boxed{3.6921037570454724}\)

Steps

Step 1 :We are given the equation \(f(x) = \ln(x) + x - 5 = 0\) and we are asked to find the root of this equation using Newton's method. The iterative formula for Newton's method is \(x_{n+1} = x_n - \frac{f(x_n)}{f'(x_n)}\).

Step 2 :The derivative of \(f(x)\) is \(f'(x) = \frac{1}{x} + 1\).

Step 3 :We are given that \(x_0 = 8\), and we need to find \(x_2\). This means we need to apply the iterative formula twice.

Step 4 :First, we find \(x_1\) using the formula: \(x_{1} = x_0 - \frac{f(x_0)}{f'(x_0)}\). Substituting the given values, we get \(x_{1} = 3.484940851840146\).

Step 5 :Next, we find \(x_2\) using the formula: \(x_{2} = x_1 - \frac{f(x_1)}{f'(x_1)}\). Substituting the values, we get \(x_{2} = 3.6921037570454724\).

Step 6 :Final Answer: \(x_{2} = \boxed{3.6921037570454724}\)

link_gpt