JEE Main 2021 · MathsNumerical answerNumerical valueMediumCalculation

JEE Main 25 February 2021, Shift 2, Maths Q85

Question 85 of 90 in this shift, Maths question 25 of 30, Section B.

If the curves

x = y^4

and

xy = k

cut at right angles, then

(4k)^6

is equal to ________.

Official answer

NTA final key.

Chapter: Application of Derivatives
Topic: Tangents and Normals
Idea tested: Orthogonal Intersection of Curves

Same idea in other shifts

Asked 2× in all

25 Feb 2021, Shift 1 · Q72If the curves, $\frac{x^2}{a} + \frac{y^2}{b} = 1$ and $\frac{x^2}{c} + \frac{y^2}{d} = 1$ intersect each other at an angle of $90^\circ$ ,…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.