%
%**********************
%**                  **
%**  EEE480 EXAM #1  **
%**  Spring 1998     **
%**  Problem #5      **
%**                  **
%**********************
%

%
% ROOT LOCUS
%
num = [1    2.5   -1.5 ]  % num = (s + 3) (s - 0.5)
den = [1   -5      6   ]  % den = (s - 3) (s - 2)
sys = tf(num, den)
rlocus(sys)
grid
title('Root Locus (k non-negative)')
pause

%
% COMPLEMENTARY ROOT LOCUS
%
sys = tf(-num, den)
rlocus(sys)
grid
title('Complementary Root Locus (k non-positive)')


k = roots([12.25 -43 1])

breakpt2 = (5 -2.5*k(1,1)) / (2*(1 + k(1,1)))

breakpt1  = (5 -2.5*k(2,1)) / (2*(1 + k(2,1)))