William Stein wrote:
> On Thu, Aug 28, 2008 at 11:06 PM, Robert Dodier <[EMAIL PROTECTED]> wrote:
>> On 8/28/08, William Stein <[EMAIL PROTECTED]> wrote:
>>
>>> Sage uses Maxima's solve command, and Maxima's solve
>>> command is pretty wimpy, and we (Sage developers) intend
>>> to write our own new solve command that can deal with
>>> more general equations.
>> Go nuts, man. Hope you can write it in Python since that will
>> make it easier to port to Lisp.
>>
>
> We might start with Sympy's solve command, which is in Python,
> and which also can't solve the above equations:
>
> sage: from sympy import *
> sage: x,y = var('x,y')
> sage: sympy.solve([x==0, 1-exp(y)==0],[x,y])
> {}
> sage: solve([y*sin(x)==0, cos(x)==0],x,y)
> {}
>
For reference, it seems that axiom can't solve these either (at least
with my naive attempts):
(9) -> solve([x=0,1-exp(y)=0],[x,y])
(9) ->
(9) [[]]
Type: List List Equation Expression
Integer
(10) -> solve([y*sin(x)=0,cos(x)=0],[x,y])
(10) ->
(10) [[]]
Type: List List Equation Expression
Integer
while mathematica gives solutions:
In[1]:= Solve[{x == 0, 1 - Exp[y] == 0}, {x, y}]
Solve::ifun: Inverse functions are being used by Solve, so some
solutions may
not be found; use Reduce for complete solution information.
Out[1]= {{x -> 0, y -> 0}}
In[2]:= Solve[{y*Sin[x] == 0, Cos[x] == 0}, {x, y}]
Solve::ifun: Inverse functions are being used by Solve, so some
solutions may
not be found; use Reduce for complete solution information.
-Pi Pi
Out[2]= {{y -> 0, x -> ---}, {y -> 0, x -> --}}
2 2
Jason
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