Newton Raphson Method on Fortran90

jhosamelly

Here's what I need to do:

"Compare the effectiveness of the bisection method and Newton’s method for the
equation x^3−2x−2 = 0 which has a single root between x=−4 and x = 2."

So far I've done

ok. this is working but of course I need to do iteration which I don't know how. Can someone teach me please? I'm trying the Newton-Raphson Method first.

Thanks for the help in advance.

EDITED: Sorry, I posted the wrong pic earlier. Here's the correct one.

gsal

Code:

program nr
real:: x, xnew, err

write(*,*) "starting x?:"
read(*,*) x

do
    xnew = x - ( (x**3 - (2*x) - 2) / ( ( 3*(x**2) )-2) )
    err = 100*abs( (xnew-x)/x )
    x = xnew
    write(*,*) "x = ", xnew, "  error = ", err
    if (err < 0.000001) exit
end do

end program nr

jhosamelly

thanks :))) Is that the iteration already?

gsal

Yes.

Isn't it? Run it and verify the solution

Similar Threads for: Newton Raphson Method on Fortran90
Thread	Forum	Replies
Newton-Raphson method	Calculus & Beyond Homework	12
Newton–Raphson method - Finite difference method	Differential Equations	5
Help with Newton-Raphson Method	Engineering, Comp Sci, & Technology Homework	9
Newton-Raphson method	Calculus & Beyond Homework	6
Newton-Raphson method for y=1/f(x)	General Math	2

jhosamelly Blog Entries: 1	thanks :))) Is that the iteration already?

gsal	Newton Raphson Method on Fortran90 Yes. Isn't it? Run it and verify the solution