Ticket #2617 (new defect)

Opened 10 months ago

Last modified 9 months ago

solve() can return undefined points as "solutions"

Reported by: cwitty Assigned to: was
Priority: critical Milestone: sage-3.4
Component: calculus Keywords:
Cc:

Description

Consider the following examples (reported by Dean Moore here: http://groups.google.com/group/sage-support/browse_thread/thread/5555e780a76b3343#) 

sage: solve(sin(x^2)/x == 0)
[x == 0]
sage: solve(sin(x^2)/x^2 == 0)
[x == 0]
sage: solve(sin(x^2)/x^3 == 0)
[x == 0]

None of these functions are even defined at x=0, so that should not be returned as a solution. (The first two functions can be extended to x=0 by taking limits, in which case x=0 is a solution to the first one but not the second; the third function has a vertical asymptote at x=0.)

Change History

04/12/2008 11:18:11 AM changed by mabshoff

  • priority changed from major to critical.

Is this a bug in Maxima? In that case we should report those to them? This also seams like a fairly serious issue, so I am elevating this to critical.

Cheers,

Michael