Arccosine Calculator

cos⁻¹(x) — find the angle whose cosine is x. Range [0°, 180°].

Inputs

Result

cos⁻¹(0.5)
60.000000°
  • Result (deg)60.000000
  • Result (rad)1.047198
  • Verify: cos(result)0.500000

Step-by-step

  1. cos⁻¹(0.5) = 1.047198 rad = 60.000000°.

How to use this calculator

  • Enter a value between -1 and 1.
  • Read the angle.

About this calculator

arccos (cos⁻¹) returns the angle whose cosine is the input. Domain [−1, 1]; principal range [0°, 180°] or [0, π]. Common values: arccos(1) = 0°, arccos(½) = 60°, arccos(0) = 90°, arccos(−½) = 120°, arccos(−1) = 180°.

Frequently asked

arccos is the principal inverse of cosine, restricted to make the function single-valued. Cosine is one-to-one only on [0°, 180°].

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