The Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.


Math Forum » Discussions » Inactive » comp.soft-sys.math.mathematica

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Limit[ Sign[],x->Infinity ]
Replies: 0  

Advanced Search

Back to Topic List Back to Topic List  
Jack Goldberg

Posts: 53
Registered: 12/7/04
Limit[ Sign[],x->Infinity ]
Posted: Feb 16, 2001 4:27 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hi,

I give you two examples using ver. 4.0 on a Mac and a unix system.

Limit[ Sign[x]*Sign[z],x->Infinity ]

yields Sign[z] which is good.

Limit[ Sign[x]+Sign[z],x->Infinity]

yields an expression too ugly to present to a wide audience, which is bad.
Its not a bug since

Limit[ Sign[x]+Sign[z],x->Infinity]//FullSimplify

yields 1+Sign[z] which is good.

I propose the name "buglet" to describe such "features" :-). By the way,
I tried some obvious variations on combinations of Sign[z] and Sign[x] and
found it pretty hard to predict the output.

Happy hunting

Jack








Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.