JEE Main 2022 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 28 June 2022, Shift 2, Maths Q24

Question 24 of 90 in this shift, Maths question 24 of 30, Section B.

\lim_{x\to1}\frac{\sin(3x^2-4x+1)-x^2+1}{2x^3-7x^2+ax+b}=-2

, then the value of

(a-b)

is equal to __________.

Official answer

NTA final key.

Chapter: Limits and Derivatives
Topic: L'Hopital's Rule
Idea tested: Simplifying with Standard Limits Before L'Hopital

Same idea in other shifts

Asked 13× in all

5 Apr 2026, Shift 1 · Q17The product of all possible values of $\alpha$ , for which…HardSingle correct
5 Apr 2026, Shift 2 · Q17Let $f(x)=\lim_{y\to 0}\frac{(1-\cos(xy))\tan(xy)}{y^3}$ . Then the number of solutions of the equation $f(x)=\sin x$ , $x \in \mathbf{R}$ …MediumSingle correct
7 Apr 2025, Shift 1 · Q16…MediumSingle correct
7 Apr 2025, Shift 2 · Q23For $t>-1$ , let $\alpha_t$ and $\beta_t$ be the roots of the equation…HardNumerical value
5 Apr 2024, Shift 2 · Q23Let $a > 0$ be a root of the equation $2x^2+x-2=0$ . If…HardNumerical value
8 Apr 2024, Shift 2 · Q25If $\alpha = \lim_{x \to 0^+} \left(\frac{e^{\sqrt{\tan x}} - e^{\sqrt{x}}}{\sqrt{\tan x} - \sqrt{x}}\right)$ and…HardNumerical value
31 Jan 2024, Shift 1 · Q6 $\lim_{x\to0}\frac{e^{2|\sin x|}-2|\sin x|-1}{x^2}$ MediumSingle correct
8 Apr 2023, Shift 1 · Q10 $\lim_{x\to0}\left(\left(\frac{1-\cos^2(3x)}{\cos^3(4x)}\right)\left(\frac{\sin^3(4x)}{\left(\log_e(2x+1)\right)^5}\right)\right)$ is…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.