Medium MCQ +4 / -1 PYQ · JEE Mains 2021

If $$\mathop {\lim }\limits_{x \to 0} {{{{\sin }^{ - 1}}x - {{\tan }^{ - 1}}x} \over {3{x^3}}}$$ is equal to L, then the value of (6L + 1) is

  1. A ${1 \over 6}$
  2. B ${1 \over 2}$
  3. C 6
  4. D 2 Correct answer

Solution

$$L = \mathop {\lim }\limits_{x \to 0} {{\left( {x + {{{x^3}} \over 6} + .....} \right) - \left( {x - {{{x^3}} \over 3}.....} \right)} \over {3{x^3}}}$$<br><br>$L = {1 \over 3}\left( {{1 \over 6} + {1 \over 3}} \right) = {1 \over 6}$<br><br>$\therefore$ $6L + 1 = 6.{1 \over 6} + 1 = 2$

About this question

Subject: Mathematics · Chapter: Limits, Continuity and Differentiability · Topic: Limits and Standard Results

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