Matlab Coding finding zeros without using fzero or roots function
By Sarah Rodriguez •
So i am a completely new at Matlab. I'm basically suppose to develop a function in Matlab that finds the zeros of a cubic polynomial. real and complex. I'm pasting below what I have so far.
I started off by using the bisection method and it's not working for a basic polynomial i know the roots to.
function rts = cubicxx(C)
a = C(1);
b = C(2);
c = C(3);
d = C(4);
start = 1e20;
last = -1e20;
rts = [8000 ; 8000; 8000];
rcount = 0;
f = @(x) (a).*x^3 + (b).*x^2 + (c).*x + d ;
%for loop % x(i)= % i = i+1;
%end %for rts='a' : 'c', rts, maybe something i will use later
tol = 10^(-6)
while (rcount < 4) %while true Starting off with the Bisection method. p = (start + last)/2; if f(p) == 0 rcount = rcount + 1; rts (rcount) = p; break; end if p-start <tol break; end if f(start)*f(p)> 0 start = p; else last = p; end
end endthe "rcount" is suppose to help me print the roots. Anyone's help would be greatly appreciated.
$\endgroup$ 9 Reset to default
