Thread: Please check my answer (Newton's Method)

Find the smallest positive value which satisfies x = 2.600cos(2.400x)

I used the formula

xn+1 = xn + [2.600cos(2.400xn)-xn]/[6.240sin(2.400xn)-1]

I ended up with x = 0.4900 after a few runs through but my online homework tells me this is incorrect. My calculator seems to get close to this when I use the zoom function to check though.

Your equation just one simple error. I see you have made it plus [xn + f(x)/-f'(x)], in substitution for the denominator having reversed signs. But you also need to reverse the sign for the '1' at the end as well.

Ah, thanks! That solves numerous problems throughout my homework, lol.