function?root=find_root（coef）

len=length（coef）;?%number?of?coefficients?of?the?given?polynomial.
x=100;?%?initial?guess（This?can?be?set?to?any?value?as?the?preference）
error=inf;

while（error>0.00001）?%answer?is?correct?up?to?0.00001.
?y=0;
?ydif=0;????
????for?n=0:len-1
????y=y+coef（len-n）*x^n;?%calculating?the?polynomial?value
????ydif=ydif+n*coef（len-n）*x^（n-1）;?%calculating?the?derivative?value
????end
????error=y/ydif;?%difference?between?previous?approximation?and?new?approximation?in?newtorn?rapson?method.
????x=x-y/ydif;?%newly?approximated?value?for?the?newtown?rapson?method
end

disp（x）;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件?????????622??2010-09-26?09:10??find_root.m
?????文件????????1318??2014-02-12?13:16??license.txt