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Numerical computations

Real numbers may have an exact representation (e.g. rationals, symbolic expressions involving square roots or constants like $ \pi$, ...) or approximate representation, which means that the real is represented by a rational (with a denominator that is a power of the basis of the representation) close to the real. Inside Xcas, the standard scientific notation is used for approximate representation, that is a mantissa (with a point as decimal separator) optionnally followed by the letter e and an integer exponent.

Note that the real number 10-4 is an exact number but 1e - 4 is an approximate representation of this number.


giac documentation written by Renée De Graeve and Bernard Parisse