\begin{align} \frac{dQ(t)}{dt}&=w\cdot P(t) \tag{1}\\ \frac{dP(t)}{dt}&=-w\cdot Q(t)+g\cdot \text{Mod}(A(t))^2 \tag{2}\\ \frac{dA(t)}{dt}&=-(k-i\cdot(1+n\cdot \cos(at)))A(t)\\&\quad+i\cdot g\cdot A(t)Q(t)+E(1+n\cdot \cos(bt))-iA1(t) \tag{3}\\ \end{align}
I am trying to solve these three equations by integration method taking limit 0 to 50a. but unable to solve. if anybody can solve it most welcome. Sorry for the code, i was not able to write in correct way, i hope you will not find any difficulty to understand my question.