I was able to determine obtain this easily with, Wolfram Alpha: http://www.wolframalpha.com/input/?i=...
Is it possible with Sage 5.9?
Though it is not created for that purpose, you can use interval arithmetics:
sage: f(x) = abs(x) - 4
sage: a = RIF(-infinity,infinity) ; a
[-infinity .. +infinity]
sage: a.parent()
Real Interval Field with 53 bits of precision
sage: f(a)
[-4.0000000000000000 .. +infinity]
Here you get the exact result, but note that in general, you will only get an interval that contains the image of the function.
Asked: 2013-06-22 17:08:35 +0200
Seen: 1,654 times
Last updated: Jun 23 '13
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