The correct answer is: \(xtan^{-1}x-\frac{1}{2}log(1+x^2)+C\)
Let \(I=∫1.tan^{-1}x dx\)
Taking \(tan^{-1}x\) as first function and 1 as second function and integrating by parts,we
obtain
\(I=tan^{-1}x∫1dx-∫[{(\frac{d}{dx}tan^{-1}x)∫1.dx}]dx\)
\(=tan^{-1}x.x-∫\frac{1}{1+x^2}.x dx\)
\(=xtan^{-1}x-\frac{1}{2}∫\frac{2x}{1+x^2} dx\)
\(=xtan^{-1}x-\frac{1}{2}log|1+x^2|+C\)
\(=xtan^{-1}x-\frac{1}{2}log(1+x^2)+C\)
Let \( f : (0, \infty) \to \mathbb{R} \) be a twice differentiable function. If for some \( a \neq 0 \), } \[ \int_0^a f(x) \, dx = f(a), \quad f(1) = 1, \quad f(16) = \frac{1}{8}, \quad \text{then } 16 - f^{-1}\left( \frac{1}{16} \right) \text{ is equal to:}\]
The number of formulas used to decompose the given improper rational functions is given below. By using the given expressions, we can quickly write the integrand as a sum of proper rational functions.

For examples,
