The #key# `ASIN()` function: also called the `arc sine` function #key# returns the *inverse sine* of a number. To be more specific, it returns the inverse sine of a number in the *radian float value*.

 Figure 1 shows the mathematical representation of the `ASIN()` function, and Figure 2 shows the visual representation of the `ASIN()` function.

# Syntax
```sql
ASIN(number)
```
# Parameter
This function requires a number as a parameter. The parameter must be a float value between -1 and 1, i.e., `-1 <= parameter <= 1`. 

# Return Value
`ASIN()` returns the inverse sine of a #key# number: radian float value #key# that is sent as a parameter. If the parameter is not between -1 and 1, it returns `NULL`.

# Example


/*example showing how to use ASIN(X)*/

-- positive number
select ASIN(1);

-- negative number
select ASIN(-1);

-- fractional number
select ASIN(0.6);

-- not between -1 and 1
select ASIN(3);
select ASIN(-3);


What is ASIN() in SQL?

ASIN() returns the inverse sine of a float number between -1 and 1 in radians.