Built-in solutions

Python, 17 bytes

from math import* # asin, acos,atan

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Python, 18 bytes (supports all real values)

from cmath import* #asin,acos,atan

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Vyxal, 2 bytes each

∆S # Arcsine
∆C # Arccosine
∆T # Arctangent

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Thunno 2, 2 bytes each

Æs # arcsin
Æc # arccos
Æt # arctan

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JavaScript, 29 bytes

Math.asin
Math.acos
Math.atan

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Rust

f64::asin
f64::acos
f64::atan