Calculate the value of the square root of 3 to four decimal places using the Newton-Raphson process

Newton-Raphson is used for finding a numerical solution to equations of the form f(x)=0. The question asks for the square root of 3, which algebraically looks like this: x = sqrt(3) This can be rewritten in the form f(x)=0, giving: x^2 - 3 = 0 (Note that in doing this you also create the negative solution by squaring it but this can be ignored in this question) You can now calculate the Newton function for f(x), which is: xn+1 = xn - (xn^2 - 3)/(2xn) Now choose a sensible x0, 1.5 is a good place to start as you know the answer will be in (1,2) as 1^2 = 1 and 2^2 = 4 So now you just apply the iteration until the first four decimal places do not change: x0 = 1.5 x1 = 1.75 x2 = 1.73214... x3 = 1.73205... x4 = 1.73205... So after 4 iterations the first 4 decimal places do not change. So the answer is 1.7321

WS
Answered by William S. Further Mathematics tutor

6731 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

It is given that f(x) = 2sinhx+3coshx. Show that the curve y = f(x) has a stationary point at x =-½ ln(5) and find the value of y at this point. Solve the equation f(x) = 5, giving your answers exactly


Let A, B and C be nxn matrices such that A=BC-CB. Show that the trace of A (denoted Tr(A)) is 0, where the trace of an nxn matrix is defined as the sum of the entries along the leading diagonal.


Use algebra to find the set of values of x for which mod(3x^2 - 19x + 20) < 2x + 2.


Using z=cos(θ)+isin(θ), find expressions for z^n-1/z^n and z^n+1/z^n


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning