math.cos

Three distinct suites: educational examples on the calculator page, this legacy regression count (6/6 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

STALE · Build schema 1.1.0 matches page · production binding STALE · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · CVP STALE · attestation STALE — Production CURRENT withheld · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-08.xcal. Calculation version 1.0.5. CVP 1.0.0-proposed. 4/4 golden · 2/2 CVP boundary · 2/2 invalid · 3/3 property · 3/3 metamorphic · 4/4 round-trip · 18/18 O3 · 1/1 cross-interface · 8/8 cross-calculator · 4/4 URL→result→graph · 1/1 CVP contract. digest ece0bdda8ca9. ≤2 ULP vs O3 applies to the 18 published tabulated vectors (common angles 0°…180° plus 8 seeded random angles in (−50°, 50°)). It is not a guarantee over the entire real line, including huge angles or unlisted neighborhoods of zeros.

• Golden (oracle-backed) 4 / 4
• CVP boundary 2 / 2
• Invalid input 2 / 2
• Property 3 / 3
• Metamorphic 3 / 3
• Round-trip 4 / 4
• O3 high-precision 18 / 18
• Cross-interface 1 / 1
• Cross-calculator 8 / 8
• URL → result → graph 4 / 4
• CVP contract 1 / 1
• Interfaces PASS · UI (SSR) / REST / MCP / URL→result→graph
• Interface claim Success 1/1. Integration: URL → SSR result → Live graph current point (4/4). Hydration/slider/history are URL-canonical contracts, not a live browser session.
• Assurance Core

• release artifacts aligned PASS
• schema output required declared PASS
• schema valid input executes PASS
• engine success output validates schema PASS
• rest success payload validates schema PASS

Fingerprint sha256:7381e78b8177db9fb0ef34490d71a4d188fd5a3f3cd5d6f1b69afb67feec8b61

Input schema sha256:4358979aadf77ad045bb159c234c88020d7e42b6946ea3c50a7395575c38f8bd · Output schema sha256:e3bbbf2db43fad9a1848c02f8c91b44d3a5293573b883a0ff74dcba8763cfaa4 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Tool

cos

Engine

cos

Engine build

2026-10-14

Evidence core

2026-10-14T02:50:33.742Z

Rendered

2026-10-27T06:32:23.547Z

Last reviewed

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Assumptions

• Real cosine. The published engine is forward cos(θ). Adjacent/hypotenuse is a local triangle convenience (hypotenuse > 0, adjacent ≥ 0, adjacent ≤ hypotenuse). Use Arccos for the inverse API.
• Algebraic snap applies only when the reduced angle (mod 360°) is a listed identity such as 0°, 30°, 45°, 60°, 90°. Nearby floats, including 89.99999995°, keep IEEE-754 Math.cos.

Limitations

• Missing theta → MISSING_REQUIRED_INPUT
• unit must be deg|rad → INVALID_UNIT