$\mathrm {\int \dfrac{1+\tan ^{2} x}{(1-\tan x)^{2}} d x}$ এর মান কোনটি ?

$\mathrm {\dfrac{-1}{1+\tan x}+c}$

$\mathrm {\dfrac{-1}{1-\tan x}+c}$

$\mathrm {\dfrac{1}{1-\tan x}+c}$

$\mathrm {\dfrac{1}{1+\tan x}+c}$