CAS problem with solution

[salvomic]

(03-05-2015 03:20 PM)Helge Gabert Wrote:  What is the difference? Try factoring polynomials with complex solutions with "use i" checked and unchecked, e.g.

factor(x^4 +1), or
solve(x^4+1=0,x)

yes, I see (it introduces complex calculation and i in the factorization), but in some cases it can be simplified, like with factor() above (not the solve following)...
With sqrt(X*X+2X+1)-sqrt(X*X) with or without, we have different results.

So, I really don't know what's better