%
% File name: polyzeros.m
% Author: Suh-Yuh Yang at NCU 
% Date: September 21, 2018  
%
clear all;
format long;
p = [1, -12, 47, -60, 24.0];
r = roots(p)
x = -1.0:0.01:10.0;
y = x.^4 -12*x.^3 + 47*x.^2 - 60*x + 24.0;
plot(x, y);
%axis([-2, 6, -30, 20]);
axis([0, 1.5, -0.5, 1]);
grid on; 
title('zeros of p(x) = x^4 -12x^3 + 47x^2 - 60x') 