% script to find eigenvalues in problem 4 on M421 Final Exam Fall 07

g = @(z) cos(z) + 1 ./ cosh(z)

z=0:0.01:10;
plot(z,g(z)), grid on, xlabel('z=\omega^{1/2}')

format long g

zsoln = [fzero(g,1,2) fzero(g,4,5) fzero(g,7,8)]
%zsoln =
%          1.87510406871196  4.69409113297418  7.85475743823761

omsoln = zsoln.^2
%omsoln =
%          3.51601526850015  22.0344915646668  61.6972144135491