# CSC

**The CSC function returns the cosecant of a number given in radians.**

This function takes a single [Number](../../variable-data-types/the-number-variable-data-type) as input. It parses that Number in radians and outputs its cosecant.

#### Declaration

```javascript
CSC(number) -> cosecant
```

&#x20;

#### Parameters

**number**(required, type: `Number`) The number to calculate the cosecant of. This number is parsed in radians.

#### Return Values

**cosecant**(type: `Number`) The cosecant of the given number.

#### Examples

The following example returns the cosecant of 45. Note that while the secant of 45 degrees is √2, the tangent of 45 radians is 1.175221363135749 and this is the number the CSC function returns:

```javascript
CSC(45) -> 1.175221363135749
```

In order to calculate the cosecant of a number of degrees, said number must first be converted into radians using the function [RADIANS](radians). The following example returns the cosecant of forty-five degrees by first converting forty-five degrees into radians and then calculating the cosecant of the resulting number. Note that the output is a numerical estimation of √2:

```javascript
CSC(RADIANS(45)) -> 1.414213562373095
```

Mathematically, the cosecant of 0 radians is undefined, and so when 0 is given as input for the SEC function, it outputs NULL, such as in the following example:

```javascript
SEC(0) -> NULL
```

#### Discussion

Mathematically, the cosecant of an angle is the reciprocal of the sine of that angle. The relationship between the functions CSC and [SIN](sin) is the same, such that, for some number n:

```javascript
CSC(n) = 1/SIN(n)
```
