Radians

Radian Measure

An angle measurement where one radian equals the angle subtended by an arc equal in length to the radius.

技術的詳細

Radians functions relate angles to side ratios in right triangles. In computing, angles are typically in radians (π radians = 180°). Key identities: sin²θ + cos²θ = 1, sin(2θ) = 2sinθcosθ. Applications include wave generation (audio synthesis), rotation transforms (2D/3D graphics), signal processing (Fourier analysis), and geolocation (haversine formula for great-circle distance). JavaScript's Math.sin() expects radians, so convert degrees with: radians = degrees × π / 180.

例

```
Trigonometric functions (right triangle):

  sin(θ) = opposite / hypotenuse
  cos(θ) = adjacent / hypotenuse
  tan(θ) = opposite / adjacent

  For a 30° angle:
  sin(30°) = 0.5,  cos(30°) ≈ 0.866,  tan(30°) ≈ 0.577

  Radians: 180° = π rad → degrees × π / 180 = radians
```

Categories

Radians

技術的詳細

例

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