Posted by Subhotosh Khan on October 26, 2002 at 14:08:56:
In Reply to: true, but... posted by Denis Borris on October 26, 2002 at 12:51:25:
: : : x = (8 +- sqrt(928 - 18k)) / 18
: : perhaps it is because some of us want to know all four solutions; real, complex, rational, integer, et.al.
: ...it does tell you stuff like: k must be < 52 (18*52=936) in order for
: solution to be real...
: would be useful as an analysis tool if this equation had to be programmed
: in a real number "looper": if x^4 - x^3 > 51 then get d'hell outta here...
: right, Joel :)
: (for me anyway: I still use an old 486)
****************************************
Actually, for computers (or by hand) there is much better way.You don't need a looper.
There is a numerical-method (I think it is called Newton-Bashforth) where any rational polynomial is factorized into quadratic polynomials. From there finding zeros is a hop, skip and jump....