# System Functions

ASN( ) | Return Arc-Sine

## Format

ASN(num[,ERR=stmtref])
Where:

num | Numeric expression (range -1 to +1) whose Arc-Sine is to be returned.
stmtref | Program line number or statement label to which to transfer control.
#### Note: The value to be supplied must be in Radians, not Degrees. To convert Degrees to Radians: Radians = Degrees * pi / 180 Degrees = Radians * 180 / pi

## Returns

Numeric value, range -ð/2 to +ð/2.

## Description

The ASN( ) function returns the Arc-Sine of the given numeric expression num. The function returns a value between -ð (negative pi) divided by 2 and +ð (+pi) divided by 2, rounded to the current PRECISION in effect. This is the inverse of the SIN( ) function.

If num is not in the range -1 to +1 inclusive, the result will be Error #40: Divide check or numeric overflow.

## Example

for I=-1 to 1 step .1
print asn(I),
next
print "DONE"
end
->run
-1.57-1.12-0.93-0.78-0.64-0.52-0.41-0.3-0.2-0.1 0 0.1 0.2 0.3 0.41 0.52 0.64 0.7 8 0.93 1.12 1.57 DONE