function y = X2DOT(u)
F = u(1);
X3 = u(2);
X4 = u(3);
L = 0.6; % panjang batang pendulum [m]
M = 0.25; % berat kereta [kg]
m = 0.1; % berat pendulum [kg]
g = 10; % percepatan gravitasi [m/sec2]
y = (F - (0.5*m*g*sin(2*X3)) + (m*L*(X4^2)*sin(X3)))/(M + (m*(sin(X3))^2));