dsolve({diff(diff(x(t),t),t) = (3*cos(a*t+b)^2-1)*c^2*x(t)+3/2*c^2*y(t)*sin(2*a*t*b), diff(diff(y(t),t),t) = (3*sin(a*t+b)^2-1)*c^2*y(t)+3/2*c^2*x(t)*sin(2*a*t*b)})