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• → RealAbs

Rationalize

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Rationalize[x]

converts a real number x to a nearby rational number with small denominator.

Rationalize[x, $d_x$]

finds the rational number lies within $d_x$ of x.

• • Rationalize[2.2]

For negative x, -Rationalize[-x] == Rationalize[x] which gives symmetric results:

• • Rationalize[-11.5, 1]

Not all numbers can be well approximated.

• • Rationalize[N[Pi]]

Find the exact rational representation of N[Pi]

• • Rationalize[N[Pi], 0]