ExamBro
ExamBro
JEE Mains · Maths · STD 12 - 8. Application and integration

Let \(f:(1,\infty)\to\mathbb{R}\) be a function defined as \(f(x) = \dfrac{x-1}{x+1}\). Let \(f^{i+1}(x) = f(f^i(x))\), \(i=1, 2, \ldots, 25\), where \(f^1(x)=f(x)\). If \(g(x) + f^{26}(x) = 0\), \(x \in (1, \infty)\), then the area of the region bounded by the curves \(y=g(x)\), \(2y=2x-3\), \(y=0\) and \(x=4\) is:

  1. A \(\dfrac{1}{8} + \log_e 2\)
  2. B \(\dfrac{1}{4} + \log_e 2\)
  3. C \(\dfrac{5}{6} + 3\log_e 2\)
  4. D \(\dfrac{5}{6} + \log_e 2\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\dfrac{1}{8} + \log_e 2\)

Step-by-step Solution

Detailed explanation

Given \(f(x) = \dfrac{x-1}{x+1}\). Let us find the first few compositions of \(f(x)\): \(f^2(x) = f(f(x)) = \dfrac{\dfrac{x-1}{x+1}-1}{\dfrac{x-1}{x+1}+1} = \dfrac{x-1-x-1}{x-1+x+1} = \dfrac{-2}{2x} = -\dfrac{1}{x}\)…