# csc() Function & Examples

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

## csc

#### csc(x)

Try it yourself:

```calculio
csc(2)
1 / sin(2)
```

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

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

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

---

## Calculate cosecant with csc

**csc(x)** returns the cosecant of x, defined as `1 / sin(x)`. It is the reciprocal trigonometric function used when a formula naturally contains inverse sine ratios.

## Examples and connections

`csc(pi / 2)` is 1. Use [sin](https://calcul.io/function/sin/index.md) for the direct ratio and [cot](https://calcul.io/function/cot/index.md) for another reciprocal-family function. The identity `csc(x)^2 = 1 + cot(x)^2` is useful for checking algebraic transformations.

## Domain caution

Cosecant is undefined whenever sine is zero, including integer multiples of pi. It grows without bound near those points, so values near a pole are sensitive to rounded angles. Use [pi](https://calcul.io/function/pi/index.md) to express exact radian angles and [round](https://calcul.io/function/round/index.md) only for display.

## Choosing the right function

In many numerical applications, calculating sine then dividing explicitly makes domain handling clearer. Csc is concise in symbolic formulas. Its inverse counterpart is [acsc](https://calcul.io/function/acsc/index.md); principal-value conventions mean it will not return every possible angle sharing a cosecant.

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