Built-in solutions
Python, 17 bytes
from math import* # asin, acos,atan
Python, 18 bytes (supports all real values)
from cmath import* #asin,acos,atan
Vyxal, 2 bytes each
∆S # Arcsine
∆C # Arccosine
∆T # Arctangent
Thunno 2, 2 bytes each
Æs # arcsin
Æc # arccos
Æt # arctan
JavaScript, 29 bytes
Math.asin
Math.acos
Math.atan
Rust
f64::asin
f64::acos
f64::atan
APL(Dyalog Unicode), 1 bytes SBCS
○
Left argument chooses function:
¯1○⍵ ⍝ asin
¯2○⍵ ⍝ acos
¯3○⍵ ⍝ atan
Go
13 bytes (reals only)
import."math"
// Asin
// Acos
// Atan
19 bytes (includes complex numbers)
import."math/cmplx"
// Asin
// Acos
// Atan
sclin, 14 bytes
sin_
cos_
tan_