close all
A = 1.65;
a1 = 55;
a2 = 605;

B = 32;
b1 = 27.5;
b2 = 55;

s = sym('s')                %creates symbolic variable

num = A*(a2-a1)*(b1+s)*(b2+s);        %numerator
den = (a1+s)*(a2+s)*(b1+s)*(b2+s);    %denominator


N = sym2poly(num);          %coefficients of a polynomial
D = sym2poly(den);
K= 1e7;

for i = 1:8,                %iteration with increasing values of K constant
    D(5) = D(5) + i*K;      
    w = linspace(0,314);    %frequency axis in to radians
    f = w/(2*pi);           %convertion to Hertz
    h = freqs(N,D,w);       %frequency response in s-domain 
    mag = abs(h);           %magnitude of frequency response 
    semilogy(f,mag);
    hold on
end

xlabel('Frequency (Hz)')
ylabel('Magnitude');
title('Laplace-transform frequency response')

