Re: Why is equation set can't solve in Mathematica?

*To*: mathgroup at smc.vnet.net*Subject*: [mg99721] Re: Why is equation set can't solve in Mathematica?*From*: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>*Date*: Tue, 12 May 2009 03:09:00 -0400 (EDT)*References*: <gu8ugp$6sm$1@smc.vnet.net>

Perhaps you didn't wait long enough... I didn't have the time or patience either. But, let's have a closer look. There are two equations for yx13b, so we may equate both right-hand sides and solve for yx13a. It takes a couple of minutes and then Mathematica finds a some huge answers (and a small one, 0). If you enter these in the original equations you'll have yx13b. Cheers -- Sjoerd On May 11, 12:26 pm, Weber <a.pengw... at gmail.com> wrote: > Hi, all. This problem is annoying > This: > > Solve[{yx13b == (-dg sxa yx13a + > Sqrt[-dg dx1 sxa^2 yx13a + dg px013a sxa^2 yx13a - > dg hxa sxa^2 yx13a^2 - dg sxa vx13a yx13a^2])/(dg sxa), > yx13b == (-dx3 sxb + px013b sxb - 2 dg sxb yx13a - Sqrt[ > 4 dg sxb (-dg sxb - hxb sxb - vx13b) yx13a^2 + (-dx3 sxb + > px013b sxb - 2 dg sxb yx13a)^2])/( > 2 (dg sxb + hxb sxb + vx13b))}, {yx13a, yx13b}] > > can't solve. Why?