Barton Willis wrote:
> -----maxima-bounces at math.utexas.edu wrote: -----
>
>
>>Define
>> a=f1(x,y,z,a,b)
>> b=f2(x,y,z,c,d)
>>x,y,z are independent variables
>>a-d are symbolic constants
>>
>>I would like to symbolically evaluate (a+b) or (a-b)
>
>
> Maybe you want to define f1 and f2 to
> be functions; you can do that with the inputs:
>
> (%i1) f1(x,y,z,a,b) := (x-a)^2 + (y-b)^2 + z^2$
>
> (%i2) f2(x,y,z,c,d) := (x-c)^2 + (y-d)^2 + z^2$
>
> To compute f1(x,y,z,a,b) - f2(x,y,z,c,d), use
>
> (%i3) f1(x,y,z,a,b) - f2(x,y,z,c,d);
> (%o3) -(y-d)^2+(y-b)^2-(x-c)^2+(x-a)^2
>
> To expand and cancel like terms, use the function 'expand'
>
> (%i4) expand(%);
> (%o4) 2*d*y-2*b*y+2*c*x-2*a*x-d^2-c^2+b^2+a^2
>
> Maybe this helps---I'm partially guessing about what you want to do.
> Another thing--the Maxima assignment operator is the colon, not equal.
>
> Barton
>
YES. And it demonstrated that my system of quadratic equations actually
reduces to a set of linear equations. Makes life much simpler.
A recommended survey of Maxima? The help system has too much fine detail
for where I'm at at the moment.
Thanks.