How can I plot this second-order differential equation

here is my start

for t1 = 0:100

for omega = 0.8:0.1:1.5

rhs = @(t,y) [y(2); -0.2.*y(2) + y - y.^3 + 0.3*cos(omega.*t)];

[t1, omega] = ode45(rhs, [0 6], omega);

plot (t1, omega);

end

end

could you help me?

Answer 1

[Alan Stevens]

More like this perhaps

omega = 0.8:0.1:1.5;
n = numel(omega);

for i = 1:n
    dydt = @(t,y) [y(2); -0.2*y(2) + y(1) - y(1).^3 + 0.3*cos(omega(i)*t)]; 
    tspan = [0 100];
    IC = [0 0];
    [t, Y] = ode45(dydt,tspan,IC);
    y = Y(:,1);
    figure
    plot(t,y),grid
    xlabel('t'),ylabel('y')
    title(['\omega = ',num2str(omega(i))])  
end