newton's method plotting
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here is my code typed out. the hw prompt is below with pictures of my code in mat lab. i keep receiving an error message. once i get the plot to work, i will be able to input my guesses.
inside funq2.m
function (y)=funq2(x);
y=sin(x)-xcos(x);
end
inside citizenone.m
x=-3:0.01:3;
(y)=funq2(x);
plot(x,y)
grid on
5 Comments
Walter Roberson
on 11 Dec 2020
Justin comments:
I keep receiving emails to accept the answer for this question. The person did not answer it, I found the answer on my own. Please stop emailing me to accept an answer that was not an answer. Thank you.
Walter Roberson
on 11 Dec 2020
Justin:
You could post the solution you found as an Answer and then Accept your Answer.
Answers (1)
David Hill
on 8 Dec 2020
Something like this:
f=@(x)sin(x)-x.*cos(x);
fp=@(x)cos(x)+x.*sin(x)-cos(x);
x=-3:.01:3;
plot(x,f(x));
%% Newton's Method
X(1)=initialGuess;%provide an initial guess
error=1;
tol=1e-6;%provide a tolerance
count=1;
while error>tol
X(count+1)=X(count)-f(X(count))/fp(X(count));
error=abs(X(count+1)-X(count));%or however you want to determine the error
count=count+1;
end
3 Comments
David Hill
on 8 Dec 2020
You are suppose to use Newton's method to solve. Have you studied Newton's method? I suggest you look at it: https://en.wikipedia.org/wiki/Newton%27s_method
I did not provide a complete solution. You need to plug in your initial guess for the root. The final answer will be in the end of the X array.
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