The Laplace transform of a function f(t) is given by \(F(s)=ln\left( {\frac{{s\; + \;1}}{{s\; + \;2}}} \right)\). Then f(t) for t > 0 is
1
\(\frac{{{e^{ - 2t}}\;-\;{e^{ - t}}}}{t}\)
2
\(\frac{{{e^{ - t}}\;-\;{e^{ - 2t}}}}{t}\)
3
2[e-2t – e-t]
4
t[e-t – e-2t]