To find: Value of sec-1\(\left(\cfrac{\text x^2+1}{\text x^2-1}\right)\)
sec-1(x2 +1)/(x2 - 1)
The formula used: (i) cos θ = sin\(\left(\cfrac\pi2-\theta\right)\)

Now, we can see that sec-1\(\left(\cfrac{\text x^2+1}{\text x^2-1}\right)\) = π - 2 tan-1x
Now Differentiating
