Let \(f\left( x \right) = x{e^{ - x}}\). The maximum value of the function in the interval (\(0,\;\infty\)) is
1
\({e^{ - 1}}\)
2
\(e\)
3
\(1\;-\;{e^{ - 1}}\)
4
\(1\; + \;{e^{ - 1}}\)
Let \(f\left( x \right) = x{e^{ - x}}\). The maximum value of the function in the interval (\(0,\;\infty\)) is