Arcsine Calculator

sin⁻¹(x) — find the angle whose sine is x. Domain [-1, 1], range [−90°, 90°].

Inputs

Result

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How to use this calculator

  • Enter a value between -1 and 1.
  • Read the angle in your chosen unit.

About this calculator

arcsin (sin⁻¹) returns the angle whose sine is the input. Domain is [−1, 1]; outside this range there is no real solution. Principal range is [−90°, 90°] (or [−π/2, π/2] in radians).

Frequently asked

Why is the range only -90° to 90°?+
Sine isn't one-to-one over its full domain — sin(30°) = sin(150°). The "principal" arcsin returns the value in [−90°, 90°] for uniqueness.
What if my input is outside [-1, 1]?+
No real solution; the calculator shows "—". sin only returns values in [−1, 1].
Common values to remember?+
arcsin(0) = 0°, arcsin(½) = 30°, arcsin(√2/2) = 45°, arcsin(√3/2) = 60°, arcsin(1) = 90°.
Is arcsin the same as 1/sin?+
No — 1/sin is cosecant (csc). arcsin is the inverse function.
Can I get an answer in radians?+
Yes — toggle the output unit to "Radians".

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