JEE Main 2021 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 17 March 2021, Shift 1, Maths Q84

Question 84 of 90 in this shift, Maths question 24 of 30, Section B.

If the function

f(x)=\frac{\cos(\sin x)-\cos x}{x^{4}}

is continuous at each point in its domain and

f(0)=\frac{1}{k}

, then k is __________.

Official answer

NTA final key.

Chapter: Continuity and Differentiability
Topic: Continuity and Differentiability
Idea tested: Limits via Series Expansion for Continuity

Same idea in other shifts

Asked 4× in all

7 Apr 2025, Shift 2 · Q25If the function $f(x)=\frac{\tan(\tan x)-\sin(\sin x)}{\tan x-\sin x}$ is continuous at $x=0$ , then $f(0)$ is equal to ________.HardNumerical value
5 Apr 2024, Shift 1 · Q7If the function $f(x)=\frac{\sin3x+\alpha\sin x-\beta\cos3x}{x^3}$ , $x\in\mathbb{R}$ , is continuous at $x=0$ , then $f(0)$ is equal to :MediumSingle correct
22 Jul 2021, Shift 2 · Q65Let $f:\mathbf{R}\to\mathbf{R}$ be defined as…HardSingle 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.