[math]\displaystyle{ \left ( \tan x \right )' =\sec^2 x x }[/math]
[math]\displaystyle{ \left ( \sec x \right )'=\sec x\,\tan x }[/math]
[math]\displaystyle{ \left ( \cot x \right )'=-\csc^2 x }[/math]
[math]\displaystyle{ \left ( \csc x \right )'=- \csc x\,\cot x }[/math]