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JEE Main 2020 · MathsMultiple choiceSingle correctMediumMulti-step

JEE Main 2 September 2020, Shift 2, Maths Q69

Question 69 of 75 in this shift, Maths question 19 of 25.

If the equation

\cos^4\theta+\sin^4\theta+\lambda=0

has real solutions for

\theta

, then

\lambda

lies in the interval :

(1) $\left(-\frac{1}{2},-\frac{1}{4}\right]$
(2) $\left[-1,-\frac{1}{2}\right]$ Official answer
(3) $\left(-\frac{5}{4},-1\right)$
(4) $\left[-\frac{3}{2},-\frac{5}{4}\right]$

Official answer

Option 2

NTA final key (Sep 2020).

Chapter: Trigonometric Functions
Topic: General Solutions
Idea tested: Fourth Power Identity Application

Same idea in other shifts

Asked 2× in all

27 Aug 2021, Shift 2 · Q89Let S be the sum of all solutions (in radians) of the equation $\sin^4\theta + \cos^4\theta - \sin\theta\cos\theta = 0$ in $[0, 4\pi]$ .…MediumNumerical value

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.