- #1

- 1,007

- 76

## Homework Statement

Find a double root of the equation ## f(x)= x^3+15.87x+24.34 ## correct to 3 decimal places.

## Homework Equations

By Newton Raphson's Formula,

## x_{n+1}=x_n + \frac{f(x_n)}{f'(x_n)} ##

##f'(x)=3x^2+15.87 ##

## The Attempt at a Solution

Does a double root means to find two roots or a root which is repeated two times?

I checked analytically with my calculator and this equation has 1 real root and 2 complex roots.

So how to proceed?