Skip to content
Worked Examples · Example 10

Q.Evaluate lim⁡x→0(e2x−1)−ln⁡(1+3x)x\displaystyle\lim_{x\to0}\frac{(e^{2x}-1)-\ln(1+3x)}{x}.

West Bengal WbchseTextbookSubjectiveImportance★★★★★est
71% · 10/14 Questions
🔒 Locked · start free trial →

You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.

Start your 14-day free trial to unlock the full solution →

Rewrite the single fraction as a difference of two fractions (valid since both share the same denominator xx):

(e2x−1)−ln⁡(1+3x)x=e2x−1x−ln⁡(1+3x)x.\frac{(e^{2x}-1)-\ln(1+3x)}{x} = \frac{e^{2x}-1}{x} - \frac{\ln(1+3x)}{x}.

By the algebra of limits' difference rule (§3), the limit of this difference is the difference of the two limits, PROVIDED each piece's limit exists on its own:

lim⁡x→0(e2x−1)−ln⁡(1+3x)x=lim⁡x→0e2x−1x−lim⁡x→0ln⁡(1+3x)x.\lim_{x\to0}\frac{(e^{2x}-1)-\ln(1+3x)}{x} = \lim_{x\to0}\frac{e^{2x}-1}{x} - \lim_{x\to0}\frac{\ln(1+3x)}{x}.

Each piece is a scaled standard limit from §5: lim⁡x→0e2x−1x=2\lim_{x\to0}\dfrac{e^{2x}-1}{x}=2 (using k=2k=2) and lim⁡x→0ln⁡(1+3x)x=3\lim_{x\to0}\dfrac{\ln(1+3x)}{x}=3 (using k=3k=3).

Combining: …

Unlock everything free for 14 days

  • Full step-by-step solutions
  • Concept-first explanations
  • Methods, shortcuts & mistakes
  • PYQ mapping + timed mock tests

Full access for 14 days. No credit card required.