Answer
$-csch(\ln t) +C$
Work Step by Step
As we are given that $\int \dfrac{csch(\ln t) coth(\ln t) dt}{ t}$
Re-write: $\int \dfrac{csch(\ln t) coth(\ln t) dt}{ t}= \int [csch(\ln t) coth(\ln t)](\dfrac{ dt}{ t})$
Now, consider $\ln t =a$ and $da= \dfrac{ dt}{ t}$
This implies , $\int csch(\ln t) coth(\ln t)(\dfrac{ dt}{ t})= \int (csch a ) (coth a) da=- csch a +C=-csch(\ln t) +C$
