Question Detail
Question
What expression represents d/dx[ln(tanx)]?
Correct Answer
Option B is the correct answer.
Detailed Explanation
d/dx[ln(tanx)] = sec²x/tanx = 1/(sinx cosx) = secx·cosecx.
Hint
Use d/dx[ln u]=u'/u with u=tan x, then simplify the resulting trig ratio.