ExamBro
ExamBro
MHT CET · Maths · Application of Derivatives

Let \(\mathrm{f}(x)=\int \frac{x^2-3 x+2}{x^4+1} \mathrm{~d} x\), then function decreases in the interval

  1. A \((-\infty,-2)\)
  2. B \((-2,-1)\)
  3. C \((1,2)\)
  4. D \((2, \infty)\)
Verified Solution

Answer & Solution

Correct Answer

(C) \((1,2)\)

Step-by-step Solution

Detailed explanation

\(\mathrm{f}(x)=\int \frac{x^2-3 x+2}{x^4+1} \mathrm{~d} x \)
\( \Rightarrow \mathrm{f}^{\prime}(x)=\frac{x^2-3 x+2}{x^4+1} \)
For \(\mathrm{f}(x)\) to be decreasing,
\(\mathrm{f}^{\prime}(x) < 0 \)
\( \Rightarrow \frac{x^2-3 x+2}{x^4+1} < 0 \)
\( \Rightarrow \frac{(x-1)(x-2)}{x^4+1} < 0 \)
\( \Rightarrow(x-1)(x-2) < 0 \)
\( \Rightarrow x \in(1,2) \)