How to use Newton's method?

Follow the steps below to learn how to use Newton's Method in Excel.

We are going to use Newton Method to solve the equation x^2=5

First you need to label the column like this

first

 

Note: (x), a column for the function evaluations (f(x)), and a column for the slope (f\’(x))

Enter value in (x). In column B write the formula =A2^2-5 and in column C write the formula 2*A2

second

In column A cell A3 enter formula =A2-B2/C2. Select cell B2, move cursor to the bottom right, a black plus sign will appear. Drag the black plus sign to cell B7.

third

Repeat with cell C2.

fourth

Repeat with cell A1. Thats it, you have now learned how to use Newton Method in Excel.

fifth

Note: Once the value of x stops changing from row to row and f(x) is small (close to zero), you have the solution (assuming the process converged).

sixth

Note: Answer is shaded in yellow.