यदि cot θ = 3/4 है, तो sin 3θ का मान ज्ञात कीजिए।  

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RRB NTPC Graduate Level CBT-I Official Paper (Held On: 06 Jun, 2025 Shift 3)
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  1. \(\frac{44}{125}\)
  2. \(\frac{81}{125}\)
  3. \(\frac{-117}{125} \)
  4. \(\frac{117}{125}\)

Answer (Detailed Solution Below)

Option 1 : \(\frac{44}{125}\)
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Detailed Solution

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दिया गया है:

cot θ = 3/4

प्रयुक्त सूत्र:

sin 3θ = 3sin θ - 4sin3 θ

गणना:

cot θ = 3/4

⇒ tan θ = 4/3

⇒ sin θ = 4/5

⇒ sin3 θ = (4/5)3 = 64/125

⇒ sin 3θ = 3 × (4/5) - 4 × (64/125)

⇒ sin 3θ = 12/5 - 256/125

⇒ sin 3θ = 300/125 - 256/125

⇒ sin 3θ = 44/125

∴ सही उत्तर विकल्प (1) है।

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