# Newton's Method Help

• June 21st 2008, 12:32 AM
name101
Newton's Method Help
Hello.
I'm doing study for a Maths test we have coming up.
And i have been stumped on this Question.

Solve $ln(x) = x^3 - 2$ by using two applications of Newtons method

• June 21st 2008, 03:25 AM
kalagota
Quote:

Originally Posted by name101
Hello.
I'm doing study for a Maths test we have coming up.
And i have been stumped on this Question.

Solve $ln(x) = x^3 - 2$ by using two applications of Newtons method

Let $f(x) = \ln x - x^3 +2$..
Then $f'(x) = \frac{1}{x} - 3x^2$
Let $x_0$ be your initial guess..
$x_1 = x_0 - \frac{f(x_0)}{f'(x_0)}$ and
$x_2 = x_1 - \frac{f(x_1)}{f'(x_1)}$