# sin() Function & Examples

Use the sin() trigonometry function in Calcul.io. Review its syntax, edit working examples, understand the result, and explore related math functions.

## sin

#### sin(x)

Try it yourself:

```calculio
sin(2)
sin(pi / 4) ^ 2
sin(90 deg)
sin(30 deg)
sin(0.2)^2 + cos(0.2)^2
```

[asin](https://calcul.io/function/asin/index.md)

[cos](https://calcul.io/function/cos/index.md)

[tan](https://calcul.io/function/tan/index.md)

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## sin(): Sine of an Angle

**sin()** returns the vertical coordinate of an angle on the unit circle. It models oscillation, rotation, waves, and periodic motion; sin(0) is 0 and sin(π/2) is 1.

## Radians and inverse use

Use radians consistently. Recover a principal angle with [asin()](https://calcul.io/function/asin/index.md), or use [atan2()](https://calcul.io/function/atan2/index.md) when coordinates determine the quadrant. Pair sin with [cos()](https://calcul.io/function/cos/index.md) for circular motion.

Real sine values lie between −1 and 1. Normalize measured ratios before inverse trigonometry, and use [abs()](https://calcul.io/function/abs/index.md) when checking amplitude magnitude.

[All functions](https://calcul.io/functions/index.md)