Value of sin 30° is:

Question

Value of sin 30° is:

1. A. √3/2
2. B. 1/√2
3. C. 1/2 (Correct answer)
4. D. 1

Correct Answer

Option C — 1/2

Detailed Solution & Explanation

The correct answer is 1/2.

Key Points

• sin 30° = 1/2, a standard value derived from the 30-60-90 triangle whose sides are in the ratio 1 : √3 : 2.
• The side opposite 30° is the shortest, giving sin 30° = 1/2.

Additional Information

• The table to memorise for 0°, 30°, 45°, 60°, 90°:
  • sin: 0, 1/2, 1/√2, √3/2, 1
  • cos: 1, √3/2, 1/√2, 1/2, 0 — the same values reversed
  • tan: 0, 1/√3, 1, √3, undefined
• Note sin 30° = cos 60° = 1/2, an instance of sin θ = cos (90° − θ).
• tan 90° is undefined, not infinity, because cos 90° = 0.