ExamBro
ExamBro
AP EAMCET · Maths · Binomial Theorem

To find the coefficient of \(x^4\) in the expansion of \(\frac{3 x}{(x-2)(x-1)}\), the interval in which the expansion isvalid, is

  1. A \(-2 < x < \infty\)
  2. B \(-\frac{1}{2} < x < \frac{1}{2}\)
  3. C \(-1 < x < 1\)
  4. D \(-\infty < x < \infty\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(-1 < x < 1\)

Step-by-step Solution

Detailed explanation

Given, \(\frac{3 x}{(x-2)(x-1)}\) can be written as \(\frac{6}{x-2}-\frac{3}{x-1}\) \(\begin{aligned} & \therefore \frac{3 x}{(x-2)(x-1)}=\frac{6}{x-2}-\frac{3}{x-1} \\ & =6(x-2)^{-1}-3(x-1)^{-1} \\ & =-3\left(1-\frac{x}{2}\right)+3(x-1)^{-1} \end{aligned}\) It is valid iff…