BITSAT 2023 · Paper 2 · Mathematics · Indefinite Integration
∫ ^ -1 x dx is equal to
∫tan−1xdx is equal to
Options
A(x+1)tan−1x−x+C
Bxtan−1x−x+C
Cx−xtan−1x+C
Dx−(x+1)tan−1x+C
Correct answer
A. (x+1)tan−1x−x+C
Step-by-step solution
We have, I=∫1⋅tan−1xdx Using by parts, I=tan−1x⋅(x)−∫1+x1×2x1×xdx=xtan−1x⋅−∫(1+x)2xxdx=xtan−1x−∫((1+x)2x1+x−(1+x)2x1)dx=xtan−1x−∫2xdx+∫2x(1+x)dx=xtan−1x−x+tan−1x+C=(x+1)tan−1x−x+C