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Euler Form Calculator

Euler form of a complex number: z = r e^{iθ} = r (cos θ + i sin θ). Same engine as Complex Number. Not a CAS. Runs locally.

Instant result
Result

Enter values to calculate.

Inputs
Mode
Formula
Trust summary Engine tested · Specification checked · 18/18 tests · Production surface contract 3/3 · v1.1.0
Input interpretation
Enter values to calculate.
Result
Model
Euler / cis form of one complex number.
Scope
atan2 argument in degrees
Verification
Engine tested · 18/18 tests · Production surface contract 3/3 · Specification checked · v1.1.0
Named expert review
Optional · Not performed
Specification basis
  • ISO 80000-2:2019 Quantities and units — Mathematics
Specification basis
Evidence
6 golden · 4 boundary · 8 property · Production surface contract 3/3 · Artifact integrity PASS
Production
Embedded snapshot: STALE · Last attested schema matched 1.1.0 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status STALE (1 capability; 163 remain CURRENT) @ 2026-09-19T00:00:17.039Z
Semantic contract
PASS

Formulas

Core equations used by this calculator.

Eulerz = r e^{iθ}
Cise^{iθ} = cos θ + i sin θ
Identitye^{iπ} = −1
iθ in degrees (−180°, 180°]. r ≥ 0. Polar → Euler with r=1, θ=180° is Euler’s identity. Not a second complex engine. Not contour integrals.

How to use

1

Choose rect or polar

Rect uses re and im. Polar uses r and θ. Default polar 1 ∠ 180° is −1.

2

Read r e^{iθ}

Arithmetic stays on /calc/math/complex-number.

Example calculations

Common configurations with formula and result.

ϟ

Euler identity

r=1 θ=180°

e^{iπ} = −1
−1
ϟ

i

0+1i

e^{i 90°}
1 e^{i 90°}

Euler Form calculator specification

Version 1.1.0 · Engine tested

Calculation status

Review policy · Evidence

Definition
z = r e^{iθ} with θ in degrees, atan2 convention. This page is mode=euler on math.complex. Polar conversion is /complex-polar. Not complex analysis.
What it calculates
Euler / cis form of one complex number.
Inputs
  • from?
  • re?
  • im?
  • r?
  • arg_deg?
Outputs
  • re
  • im
  • r
  • arg_deg
  • euler
  • cis
Formula
z = r e^{iθ}
Assumptions
  • atan2 argument in degrees
  • r ≥ 0
  • Not a CAS
  • Not complex analysis
Units
  • dimensionless
  • degrees
Boundary conditions
  • r < 0 → VALUE_MUST_BE_NON_NEGATIVE
  • unknown mode (including log) → INVALID_MODE
Example
from=polar r=1 arg_deg=180 → −1
Validation cases

2 published on this page · 18/18 tests · Production surface contract 3/3 · View evidence

  • from=polar r=1 arg_deg=180 → re=-1 im=0
  • re=0 im=1 → r=1 arg_deg=90
Specification basis
  • ISO 80000-2:2019 Quantities and units — Mathematics
Calculation version
1.1.0
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Frequently asked questions

Key distinctions behind the calculation.

Is this a second complex engine?

No. It is mode=euler on math.complex, the same engine as /calc/math/complex-number.

Is this complex analysis?

No. It writes Euler form. Poles, residues, and contour integrals stay out of scope.