Services & Resources / Wolfram Forums
MathGroup Archive
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1999

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Can someone explain this?

  • To: mathgroup at
  • Subject: [mg19150] Re: Can someone explain this?
  • From: Bruno Daniel <bruno.daniel at>
  • Date: Thu, 5 Aug 1999 23:58:51 -0400
  • Organization: University of Karlsruhe
  • References: <7obcl4$>
  • Sender: owner-wri-mathgroup at

Hi Benjamin

Sin[x]/Cos[x] is simplified to Tan[x] whenever it occurs in an
expression. You can prevent this by wrapping it with HoldForm:

x y Tan[x] + Tan[y]     /. Tan[z_]->HoldForm[Sin[z]/Cos[z]]

x y Sin[x] / Cos[x] + Sin[y] / Cos[y]

The expression Sin[x] / Cos[x] is then kept because it is in the
Hold status. You can release all holds in an expression with

In[2]:= % // ReleaseHold
Out[2] = x y Tan[x] + Tan[y]

Yourse sincerely

  • Prev by Date: Re: DSolve Bessels
  • Next by Date: Re: DSolve Bessels
  • Previous by thread: RE: Can someone explain this?
  • Next by thread: Re: Can someone explain this?