arcsin
The trigonometric arcsine function.
Syntax

arcsin(x)

x
is a real or complex number

Description
For real values, arcsin is the inverse of the restriction of the trigonometric sine function to [−π/2, π/2]; the domain is [−1, 1].
In general, arcsin(z)
is defined as
arcsin(z) = −i⋅ln(i⋅z + √(1 − z^2))
where z
is a complex number. Notice that the general definition will be used also for real arguments outside of [−1, 1].
Examples
arcsin(√3/2)
1.0471975512 (=π/3)
arcsin(−1/2)
−0.523598775598 (=−π/6)
arcsin(2)
1.57079632679 − 1.31695789692⋅i
arcsin(i)
0.88137358702⋅i