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Saturday, 31 October

JEE Main 2026 · MathsMultiple choiceSingle correctMediumMulti-step

JEE Main 2 April 2026, Shift 1, Maths Q11

Question 11 of 75 in this shift, Maths question 11 of 25, Section A.

If sin⁡(π18)sin⁡(5π18)sin⁡(7π18)=K\sin\left(\frac{\pi}{18}\right)\sin\left(\frac{5\pi}{18}\right)\sin\left(\frac{7\pi}{18}\right)=K, then the value of sin⁡(10Kπ3)\sin\left(\frac{10K\pi}{3}\right) is :
  1. (1)3+122\frac{\sqrt3+1}{2\sqrt2}Official answer
  2. (2)3−12\frac{\sqrt3-1}{\sqrt2}
  3. (3)32\frac{\sqrt3}{2}
  4. (4)12\frac12

Official answer

Option 1

NTA final key.

Chapter
Trigonometric Functions
Topic
Trigonometric Identities
Idea tested
Sine Product Identity with 60 Degrees

Same idea in other shifts

Asked 3× in all
  1. 26 Jun 2022, Shift 1 · Q26If sin⁡2(10∘) sin⁡(20∘) sin⁡(40∘) sin⁡(50∘) sin⁡(70∘)=α−116sin⁡(10∘)\sin^2(10^\circ)\,\sin(20^\circ)\,\sin(40^\circ)\,\sin(50^\circ)\,\sin(70^\circ) = \alpha - \frac{1}{16}\sin(10^\circ), then…HardNumerical value
  2. 26 Jun 2022, Shift 2 · Q1816sin⁡(20∘)sin⁡(40∘)sin⁡(80∘)16 \sin(20^\circ) \sin(40^\circ) \sin(80^\circ) is equal to :EasySingle 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.