Domain not checked out, please see inside...

[Arno K]

(08-12-2015 04:03 PM)Aries Wrote:  

(08-12-2015 02:46 PM)Arno K Wrote:  Well, I do not think that it is not correct as I tend to simplify first, then we have (x-1)*(x+3)>=0 and the Primes answer is ok. But a real bug is the fact that it even does that with simplify set to "None", here it should exclude 1.
Arno

You may simplify first but the fraction remains, its domain is still there, it can't be ignored ;-)

Ok, clearly the domain stays the same, but this is a removable discontinuity, usually all further calculation is then done after a sentence explaining that and then using the simplified function. Here, as I explained above its a bug in the Prime and not only there, as Tim found out.
Arno