I'm talking about functions such as Python's math.frexp() :
Return the mantissa and exponent of x as the pair (m, e). m is a float and e is an integer such that x == m * 2**e exactly. If x is zero, returns (0.0, 0), otherwise 0.5 <= abs(m) < 1. This is used to “pick apart” the internal representation of a float in a portable way.
In some applications it is useful it obtain the mantissa and exponent of floating point numbers. http://www.technicalc.org/tiplist/en/files/pdf/tips/tip6_58.pdf
That said, what would be the usefulness of functions such as math.frexp() in real-world applications? What can I use it for?