A system is described by the following differential equation:
$\frac {dy(t)}{dt}+2y(t)=\frac {dx(t)}{dt}+x(t),\;x(0)=y(0)=0$
where $\text{x(t)}$ and $\text{y(t)}$ are the input and output variables respectively. The transfer function of the inverse system is
- $\frac {s+1}{s-2}$
- $\frac {s+2}{s+1}$
- $\frac{s+1}{s+2}$
- $\frac {s-1}{s-2}$