$8\_1$ Write a Matlab code $($e$.$g$.,$ develop a $.$m file$)$ to solve the following non$-$linear differential equation:

$\frac{d^{2}x}{d{t}^2}+3\frac{dx}{dt}-B{x}^2=1,x(0)=1,\frac{dx}{dt}{|}_t=0=1,$ with $B=2.$ Please plot $x$ in the range of $0$