ExamBro
ExamBro
AP EAMCET · Maths · Binomial Theorem

The coefficient of \(x^3\) in the expansion of \(\frac{x^4+1}{\left(x^2+1\right)(x-1)}\) when it is expressed in terms of positive integral powers of \(x\), is

  1. A 0
  2. B 1
  3. C 16
  4. D 24
Verified Solution

Answer & Solution

Correct Answer

(A) 0

Step-by-step Solution

Detailed explanation

\(\frac{x^4+1}{\left(x^2+1\right)(x-1)} = x+1 + \frac{2}{\left(x^2+1\right)(x-1)}\) \(= x+1 + \frac{2}{-(1-x)(1+x^2)}\) \(= x+1 - 2(1-x)^{-1}(1+x^2)^{-1}\) \(= x+1 - 2(1+x+x^2+x^3+\dots)(1-x^2+x^4-\dots)\) Coefficient of \(x^3\) in \((1+x+x^2+x^3+\dots)(1-x^2+x^4-\dots)\):…