The correct option is B sinxlog|tanx2|−x+c
∫ cosx log (tanx/2)dx
= log(tanx/2) ∫ cosx dx
−∫ 1/2 sec 2 x/2tan x/2 ∫ cosx dx
=log (tan x/2)sinx− ∫ cosecx sinx dx
= log(tan x/2) sinx− x+c
= log(tan x/2)sinx−x+c= ∫ cosx log (tan x/2)dx
=sinxlog|tanx2|−x+c
Hence, option 'D' is correct.