The value of integral \(\mathop \smallint \nolimits_0^1 \frac{{dx}}{{{e^x} + {e^{ - x}}}}\) is
1
cot-1 e
2
tan-1 e
3
\( {\tan ^{ - 1}}{e^{ }}- \frac{\pi }{4}\)
4
\( {\cot ^{ - 1}}{e^{ }}- \frac{\pi }{4}\)
The value of integral \(\mathop \smallint \nolimits_0^1 \frac{{dx}}{{{e^x} + {e^{ - x}}}}\) is