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θ = tan⁻¹(x) = tan⁻¹(y / x)

Arctan Calculator

Calculate inverse tangent tan⁻¹(x) and 2-argument atan2(y, x) direction angles.

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Formula & Mathematical Method

This calculator uses standard deterministic mathematical algorithms to process user inputs in real time. Calculations are performed client-side for maximum speed and privacy.

Reviewed by Mathematics Advisory Panel
Checked for AccuracyLast Reviewed: August 2026

Arctan & 2-Argument Atan2 Direction Angle Calculation

Theoretical background and practical computational guidance

The arctangent function tan⁻¹(x) returns the angle whose tangent is x.

Valid Domain: All real numbers (-∞, +∞).

Principal Range: (-90°, +90°) or (-π/2, +π/2) radians.

Atan2(y, x) accounts for signs of both y and x to determine exact quadrant angles in [-180°, +180°].

Arctan & Atan2 FormulasMathematical Standard
\theta = \tan^{-1}(x), \quad \theta = \text{atan2}(y, x)

Converts slope ratio or (x, y) coordinates into direction angle θ.

Worked Calculation Walkthrough & Analytical Steps

To evaluate a typical problem using the Arctan Calculator, identify your known baseline inputs, convert all measurements to congruent units, and apply the governing formula sequentially. Below is a structured breakdown of the computational workflow:

  1. Data Ingestion & Unit Harmonization: Enter the primary parameters into the input fields. If working with mixed metric or imperial dimensions, use the unit selector above to align scales.
  2. Intermediate Term Evaluation: The algorithm evaluates inner parentheses, rate exponents, and coefficient ratios in strict compliance with mathematical precedence.
  3. Final Transformation & Precision Rounding: The final numerical figure is determined, formatted to user-selected decimal precision, and mapped against relevant diagnostic or diagnostic thresholds.

Key Insights & Operational Tips

  • arctan(1) = 45° (π/4 rad), arctan(0) = 0°.
  • atan2(y, x) resolves quadrant ambiguity for vectors.

Frequently Asked Questions (FAQs)

Authoritative answers to common computational and formula questions

atan2(y, x) preserves negative sign information of both x and y separately, correctly distinguishing quadrant II (-x, +y) from quadrant IV (+x, -y).

Authoritative Citations & Institutional References

Disclaimer & Methodological Transparency Notice

Academic Notice: Supports single ratio x or coordinate pairs (x, y).