∫sin−12x1+x2dx is equal to
xtan−1x−lnsectan−1x+C
xtan−1x+lnsectan−1x+C
xtan−1x−lncostan−1x+C
None of these
I=∫sin−12x1+x2dx, let x=tanθ⇒ dx=sec2θdθ∴ I=∫sin−12tanθ1+tan2θ⋅sec2θdθ=2∫θ⋅sec2θdθ =2(θ⋅tanθ−ln∣secθ)+C =2x⋅tan−1x−lnsectan−1x+C