NDA Math Mock Test 03 – Question 65

Question:

What is \(\lim_{h \to 0} \frac{\sqrt{2x+3h} – \sqrt{2x}}{2h}\) equal to?

\(\lim_{h \to 0} \frac{\sqrt{2x+3h} – \sqrt{2x}}{2h}\) किसके बराबर है?

Options:

  • \(\frac{1}{2\sqrt{2x}}\)
  • \(\frac{\sqrt{2x}}{3}\)
  • \(\frac{3}{2\sqrt{2x}}\)
  • \(\frac{3}{4\sqrt{2x}}\)
  • \(\frac{1}{2\sqrt{2x}}\)
  • \(\frac{\sqrt{2x}}{3}\)
  • \(\frac{3}{2\sqrt{2x}}\)
  • \(\frac{3}{4\sqrt{2x}}\)

Correct Answer: d)

Explanation:

Rationalizing the numerator:
\[\frac{\sqrt{2x+3h} – \sqrt{2x}}{2h} = \frac{(2x + 3h) – 2x}{2h(\sqrt{2x+3h} + \sqrt{2x})} = \frac{3h}{2h(\sqrt{2x+3h} + \sqrt{2x})} = \frac{3}{2(\sqrt{2x+3h} + \sqrt{2x})}\]
Taking the limit as \(h \to 0\):
\[\lim_{h \to 0} \frac{3}{2(\sqrt{2x} + \sqrt{2x})} = \frac{3}{2(2\sqrt{2x})} = \frac{3}{4\sqrt{2x}}\]
Hence, the correct option is (d).

अंश का परिमेयकरण करने पर:
\[\frac{3h}{2h(\sqrt{2x+3h} + \sqrt{2x})} = \frac{3}{2(\sqrt{2x+3h} + \sqrt{2x})}\]
\(h \to 0\) सीमा लेने पर:
\[\frac{3}{2(2\sqrt{2x})} = \frac{3}{4\sqrt{2x}}\]
अतः सही विकल्प (d) है।

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top