It represents the inverse of the sine function. Recall f(x) and f-1(x). sin-1x means the same as arcsin x, i.e., the arc whose sine is x.

Is arcsin the same as inverse sin?

The arcsin function is the inverse of the sine function. It returns the angle whose sine is a given number. Means: The angle whose sin is 0.5 is 30 degrees.

Should you write arcsin or sin 1?

If you are looking for a function, arcsin(x), makes more sense to me. This always returns a value in a specified range. I always interpret sin^{-1}(x) to be a pre-image: that is, any real number y such that sin(y) = x (this is not a function, since y is not unique).

What is the difference between Sine and Inverse Sine (Arcsine)? Sine is a basic trigonometric function, and the arcsine is the inverse function of the sine.