ExamBro
ExamBro
AP EAMCET · Maths · Continuity and Differentiability

\(\mathrm{f}(\mathrm{x})\) is differentiable on \(\mathbb{R}\) and \(\mathrm{f}^{\prime}(\mathrm{m}) \neq 0, \mathrm{~m} \in \mathbb{R}\).
If \(\lim _{x \rightarrow m} \frac{x f(m)-m f(x)}{x-m}+f^{\prime}(m)=f(m)\), then \(m=\)

  1. A \(0\)
  2. B \(-1\)
  3. C \(1\)
  4. D \(2\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(1\)

Step-by-step Solution

Detailed explanation

Let \(f(x)=\frac{1}{3} x^3+2 x\) \(\Rightarrow f^{\prime}(x)=x^2+2 \neq 0 \forall x \in R\) Now, \(\lim _{x \rightarrow m} \frac{x f(m)-m f(x)}{x-m}+f^{\prime}(m)=f(m)\)…