Solve equation in matlab

What is the matlab code to solve this equation?

cos(βL)cosh(βL)= -1 for L = 1,2,3,4

And, how to plot the result?

Thanks

Answer 1

[Stephan]

% rewrite equation to be equal to zero for fsolve and save as a function handle
eqn = @(beta, L) cos(beta .* L) .* cosh(beta .* L) + 1;
% define values for L
L = 1:4;
% call fsolve
sol = fsolve(@(beta)eqn(beta,L),[1 1 1 1])
% test the quality of the result - all results should be near zero
test = eqn(sol,L)

% plot results
plot(L, sol)
xlabel('L')
ylabel('beta')

[Angam Kamei]

Thanks Stephan