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    "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."
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    "cos(0°) = 1; cos(60°) = 1/2; cos(90°) = 0; cos(180°) = −1; cos(300°) = 1/2; cos(−θ) = cos(θ)."
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