JEE Main 2021 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 26 August 2021, Shift 1, Maths Q82

Question 82 of 90 in this shift, Maths question 22 of 30, Section B.

Let a, b

\in

\mathbf{R}

, b

\neq

0. Define a function

f(x)=\begin{cases} a\sin\frac{\pi}{2}(x-1), & \text{for } x \leq 0 \\ \frac{\tan 2x-\sin 2x}{b\,x^3}, & \text{for } x>0. \end{cases}

f

is continuous at

x=0

, then

10-ab

is equal to __________.

Official answer

NTA final key.

Chapter: Continuity and Differentiability
Topic: Continuity and Differentiability
Idea tested: Continuity at a Point

Same idea in other shifts

Asked 8× in all

4 Apr 2024, Shift 1 · Q6Let $f: \mathbf{R} \to \mathbf{R}$ be a function given by…MediumSingle correct
4 Apr 2024, Shift 2 · Q8If the function $f(x)=\begin{cases}\dfrac{72^x-9^x-8^x+1}{\sqrt2-\sqrt{1+\cos x}}, & x\ne 0\\ a\log_e 2\log_e 3, & x=0\end{cases}$ is…HardSingle correct
27 Jul 2022, Shift 2 · Q5If for $p \neq q \neq 0$ , the function $f(x) = \frac{\sqrt[7]{p(729 + x)} - 3}{\sqrt[3]{729 + qx} - 9}$ is continuous at $x = 0$ , then :MediumSingle correct
30 Jul 2022, Shift 2 · Q69Let…HardSingle correct
25 Jul 2021, Shift 1 · Q65Let $f:\mathbf{R}\to\mathbf{R}$ be defined as…MediumSingle correct
9 Jan 2020, Shift 1 · Q58If…MediumSingle correct
2 Sep 2020, Shift 1 · Q59If a function $f(x)$ defined by…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.