JEE Mathematics · Hard

Trigonometry: Identity MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
IdentityHardQuestion 200041

Question

The value of sin 10° sin 50° sin 70° is:
  1. A
    1/8
    Correct
  2. B
    √3/8
  3. C
    1/4
  4. D
    1/16

Correct answer

1/8

Explanation

Use identity: sin θ sin(60°−θ) sin(60°+θ) = sin(3θ)/4. With θ = 10°: sin 10° sin 50° sin 70° = sin 30°/4 = (1/2)/4 = 1/8.