Question

What does sin^-1(x) mean or equal?

Answer 1

sin^-1(x) =arc sin of x
let y = sin^-1(x) , then
sin y=x

Answer 2

also if sin y=x , ....then y= arc sin x =sin^-1 x

Answer 3

therefore arc sin of x is the inverse of sin y and vise versa

Answer 4

sin^-1 means the angle that produces a sin value.