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A mathematical expression expressed using a finite number of basic arithmetic operations over   over the numbers and elementary functions.

The key benefit of dealing with closed-form expressions is that they are

• well tabulated with precision enough for the majority of engineering applications
• implemented as fast-computable algorithms with computer precisions (usually 64 bit and 128 bit) on modern  computers
• available as fast-computing algorithms with arbitrary user-defined precision

See also

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Formal science / Mathematics / Calculus

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