%ode_func
function[dtheta_dt]=ode_func(t,theta,b,g,l,m)
theta1=theta(1)
theta2=theta(2)
dtheta1_dt=theta2;
dtheta_dt=-(b/m)*theta2-(g/l)*sin(theta1);
dtheta_dt=[dtheta1_dt;dtheta2_dt];
end
%Program for second order differential eqn
close all
clear all
clc
b=0.05;
g=9.81;
l=1;
m=1;
%Initial condition
theta_0=[0;3];
%Time points
t_span=linspace(0,20,500);
%Solve ODE
[t,results]=ode45(@(t,theta)ode_func(t,theta,b,g,l,m),t_span,theta_0);
plot(t,results(:,1))
hold on
plot(t,results(:,2))
ylabel(\'Plot\')
xlabel(\'Time\')