Advanced structural systems - mechanical engineering

function ydot = Q4e_forced_2DOF(t,y) m1=1; m2=1; c1=1; c2=1; c3=1; k1=100; k2=400; k3=100; omega1=9; ydot = zeros(4,1); ydot(1) = y(2); ydot(2) = (1/m1)*( -(c1+c2)*y(2) + c2*y(4) - (k1+k2)*y(1) + k2*y(3) ); ydot(3) = y(4); ydot(4) = (1/m2)*( 10*cos(omega1*t) + c2*y(2) - (c2+c3)*y(4) + k2*y(1) - (k2+k3)*y(3) );