$\int \frac{d x}{2 x^{2}+x+1}=$ কত ?

$\frac{2}{\sqrt{7}} \tan ^{-1} \frac{4 x+1}{\sqrt{7}}+c$

$\frac{2}{\sqrt{7}} \ell n \frac{4 x+1}{\sqrt{7}}+c$

$\tan ^{-1} \frac{x+1}{2}+c$

$\frac{2}{\sqrt{7}} \tan ^{-1} \frac{4 x+1}{7}+c$