'solve' doesn't work!
- Subject: 'solve' doesn't work!
- From: Henry Baker
- Date: Wed, 12 Jun 2013 09:21:13 -0700
Your comment doesn't appear to me to be relevant to the particular set of equations that I gave.
The equations are all linear, and solve works fine without the extraneous equations:
(%i22) eqn12;
(%o22) [d0 = c0 + b0, d1 = c1 + b1, d2 = c2 + b2]
(%i23) d;
(%o23) [d0, d1, d2]
(%i24) solve(eqn12,d);
(%o24) [[d0 = c0 + b0, d1 = c1 + b1, d2 = c2 + b2]]
(%i25)
How can the extraneous (linear) equations screw up solve?
At 09:08 AM 6/12/2013, Stavros Macrakis wrote:
>Solve only gives solutions valid for all values of parameters (as opposed to variables). For example:
>
>(%i12) solve([x=a,x=-a],[x]); <<< no solutions for all a
>(%o12) []
>(%i13) solve([x=a,x=-a],[x,a]); <<< make a into a variable
>(%o13) [[x = 0, a = 0]]
>
>On Wed, Jun 12, 2013 at 11:38 AM, Henry Baker <hbaker1 at pipeline.com> wrote:
>Solve doesn't work, either!
>
>(%i7) d;
>(%o7) [d0, d1, d2]
>(%i8) eqns;
>(%o8) [d0 = c0 + b0, d1 = c1 + b1, d2 = c2 + b2, h0 = g0 + f0 - e0,
>h1 = g1 + f1 - e1, h2 = g2 + f2 - e2, f0 = e0 + b0, f1 = e1 + b1,
>f2 = e2 + b2, g0 = e0 + c0, g1 = e1 + c1, g2 = e2 + c2]
>(%i9) solve(eqns,d);
>(%o9) []
>(%i10)