Medium MCQ +4 / -1 PYQ · JEE Mains 2023

$\lim\limits_{n \rightarrow \infty} \frac{3}{n}\left\{4+\left(2+\frac{1}{n}\right)^2+\left(2+\frac{2}{n}\right)^2+\ldots+\left(3-\frac{1}{n}\right)^2\right\}$ is equal to :

  1. A 0
  2. B $\frac{19}{3}$
  3. C 19 Correct answer
  4. D 12

Solution

<p>$$\mathop {\lim }\limits_{n \to \infty } \sum\limits_{r = 0}^{n - 1} {{3 \over n}{{\left( {2 + {r \over n}} \right)}^2}} $$</p> <p>$= \int_0^1 {3{{(2 + x)}^2}\,dx}$</p> <p>$= \left. {3\,.\,{{{{(2 + x)}^3}} \over 3}} \right|_0^1$</p> <p>$= {3^3} - {2^3} = 19$</p>

About this question

Subject: Mathematics · Chapter: Definite Integration · Topic: Properties of Definite Integrals

This question is part of PrepWiser's free JEE Main question bank. 216 more solved questions on Definite Integration are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →