Inverse Trigonometric Functions Calculator

Calculate arcsin, arccos, arctan (sin⁻¹, cos⁻¹, tan⁻¹) to find angles from trig ratios. Returns principal values in degrees and radians. Includes all inverse trig functions.

📐 Trigonometry📐 θ = arcsin(x), arccos(x), arctan(x)🔢 Math
Function
Input value x
y (for atan2 only)
Please enter valid values.

Formula & Reference

VariableSymbolFormulaUnits
Inverse Trigonometric Functions Calculatorθ = arcsin(x), arccos(x), arctan(x)degrees / radians

Step-by-Step Examples

Example 1
arcsin

arcsin(0.5)=?

  • sin(θ)=0.5 → θ=30°
  • arcsin returns principal value in [−90°,90°]
✓ θ = 30°
Example 2
arctan

arctan(1)=?

  • tan(θ)=1 → θ=45°
  • arctan returns value in (−90°,90°)
✓ θ = 45°
Example 3
arccos

arccos(0)=?

  • cos(θ)=0 → θ=90°
  • arccos range is [0°,180°]
✓ θ = 90°

Real-World Applications

Common Mistakes to Avoid

⚠️
Input must be in [−1,1] for arcsin, arccos

arcsin(2) is undefined — sine never exceeds 1. arctan accepts any real number.

⚠️
Principal value only

arcsin returns one value (principal). All angles with the same sine: θ and π−θ. Always check which quadrant you need.

⚠️
Use atan2 not atan for full angle

atan(y/x) can't distinguish (1,2) from (−1,−2). atan2(y,x) gives correct angle in all four quadrants.

Frequently Asked Questions

What is arcsin?
The inverse function of sin, restricted to [−π/2, π/2]. arcsin(x) gives the angle whose sine is x.
What are the ranges of inverse trig functions?
arcsin: [−90°,90°]. arccos: [0°,180°]. arctan: (−90°,90°). These are principal value ranges.
What is atan2?
atan2(y,x) = arctan(y/x) but correctly handles all four quadrants. Returns angles in (−180°,180°]. Essential in programming.
Why do inverse trig functions have restricted ranges?
Trig functions are periodic and not one-to-one. To have an inverse, they must be restricted to intervals where they are strictly monotone.
How to find all solutions?
arcsin(x) gives principal value θ₀. All solutions: θ₀ + 2πk and (π−θ₀) + 2πk for any integer k.

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Formula Explorer connections

Interpretation: This relationship connects dimensions, coordinates, angles or trigonometric ratios to a geometric measurement. Assumption: Use a consistent angle mode and length unit, identify the intended shape or coordinate system, and verify that the supplied dimensions form valid geometry.

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