On 03/22/13 07:04, Barton Willis wrote:
> Try (your answer is nicer)
>
> (%i1) depends(y,x)$
> (%i2) a*x + b*y+c=0$
> (%i3) [%,diff(%,x), p^2=c^2/(a^2+b^2)]$
> (%i4) eliminate(%,[a,b])$
> (%i5) factor(%);
> (%o5) [-c^2*x^2*(x^2*('diff(y,x,1))^2-p^2*('diff(y,x,1))^2-2*x*y*('diff(y,x,1))+y^2-p^2)]
>
Thanks, but,
This does not eliminate c.
Tom Dean