arcsin(x)=1/2
1) Let's solve in ℝ: arcsin(x) = 12
arcsin takes its values in [-π2, π2], which contains 12: arcsin(x) = 12 is equivalent to x = sin(12)
Candidates, pending the domain check: x = sin(12)
2) Let's find the domain of arcsin(x) = 12
For the expression arcsin(x) to exist, you must check: |x| ≤ 1
|A| ≤ B is equivalent to -B ≤ A ≤ B
-1 ≤ x ≤ 1
Domain constraints: x ∈ [-1, 1]
▶Solution:   x = sin(12)
3) The numeric value of: x = sin(12) is:
x = sin(0.5)
ⓘ The sine is the y-coordinate (vertical axis) of the point reached on the unit circle after a rotation of 0.5 radians from the horizontal axis pointing to the right
▷ x = ≈ 0.4794