Please help me to solve this newton-raphson method
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How can I use Newton-Raphson method to determine a root of
f (x) = x5−16.05x4+88.75x3−192.0375x2+116.35x +31.6875
using an initial guess of x = 0.5825 and εs = 0.01%.
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Luis Varela
2016년 10월 4일
On Newton Raphson method, you need calculate the function f(x) and the derivate f'(x), to get the next value of x, and continue while the error is greater than desired, for example:
x = 0.5825;
e=1;
while e>0.01
fx= x^5 - 16.05*x^4 + 88.75*x^3 - 192.0375*x^2 + 116.35*x + 31.6875;
dfx= 5*x^4 - 4*16.05*x^3 + 3*88.75*x^2 - 2*192.0375*x + 116.35;
x2=x-(fx/dfx);
e=100*abs((x2-x)/x2);
x=x2;
end
At the end x will have the value of the calculated root, aprox. x=6.5
답변 (2개)
Jakub Rysanek
2016년 10월 3일
In this case I would go with
roots([1,-16.05,88.75,192.0375,116.35,31.6875])
댓글 수: 0
Luis Varela
2016년 10월 4일
On Newton Raphson method, you need calculate the function f(x) and the derivate f'(x), to get the next value of x, and continue while the error is greater than desired, for example:
x = 0.5825;
e=1;
while e>0.01
fx= x^5 - 16.05*x^4 + 88.75*x^3 - 192.0375*x^2 + 116.35*x + 31.6875;
dfx= 5*x^4 - 4*16.05*x^3 + 3*88.75*x^2 - 2*192.0375*x + 116.35;
x2=x-(fx/dfx);
e=100*abs((x2-x)/x2);
x=x2;
end
At the end x will have the value of the calculated root, aprox. x=6.5
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