#2015_13 I just started learning calculus

Calculus Level 3

\[\large { (\tan { x } ) }^{ { (\tan { x }) }^{ { (\tan { x }) }^{ { . }^{ .{ }^{ . } } } } }\]

Find the value of derivative of the function above at \(x=\frac { \pi }{ 4 } \).