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  The imaginary unit  satisfies the following relation: For evaluation of the eight classical constants  ,  ,  ,  ,  ,  ,  , and  , Mathematica uses procedures that are based on the following formulas or methods: The formula for  is called Chudnovsky's formula. The eight classical constants  ,  ,  ,  ,  ,  ,  , and  are positive real numbers. The constant  is a quadratic irrational number. The constants  ,  , and  are irrational and transcendental over  . Whether  and  are irrational is not known.
The imaginary unit  is an algebraic number. The five classical constants  ,  ,  ,  , and  have numerous series representations, for example, the following: The four classical constants  ,  ,  , and  can be represented by the following formulas: The five classical constants  , (and  ),  ,  ,  , and  have numerous integral representations, for example: The following integral is called the Gaussian probability density integral:
                         . The following integrals are called the Fresnel integrals:
                        . The six classical constants  ,  ,  ,  ,  , and  have numerous limit representations, for example: The four classical constants  ,  ,  , and  have numerous closed‐form continued fraction representations, for example: The golden ratio  satisfies the following special functional identities: The eight classical constants ( ,  ,  ,  ,  ,  ,  , and  ) and the imaginary unit  have the following complex characteristics: Derivatives of the eight classical constants ( ,  ,  ,  ,  ,  ,  , and  ) and imaginary unit constant  satisfy the following relations: Simple indefinite integrals of the eight classical constants ( ,  ,  ,  ,  ,  ,  , and  ) and imaginary unit constant  have the following values: All Fourier integral transforms and Laplace direct and inverse integral transforms of the eight classical constants ( ,  ,  ,  ,  ,  ,  , and  ) and the imaginary unit  can be evaluated in a distributional or classical sense and can include the Dirac delta function: The eight classical constants ( ,  ,  ,  ,  ,  ,  , and  ) satisfy numerous inequalities, for example: |