Re: Exponent function question
- To: mathgroup at smc.vnet.net
- Subject: [mg94420] Re: Exponent function question
- From: dimitris <dimmechan at yahoo.com>
- Date: Fri, 12 Dec 2008 06:56:46 -0500 (EST)
- References: <ghqju2$138$1@smc.vnet.net>
On 11 =C4=E5=EA, 10:44, Tuesday Shopping <tuesdayshopp... at yahoo.com> wrote: > Reposting the question (previous post did not make it for some reason) > > Consider a simple example: "Exponent[Sqrt[x^2+1], x]". This gives "0" as = output. > > I am trying to determine the maximum exponent of a given variable in an e= xpression. Is there any way to do this? I would like to get "2" as output f= or the above example. > > Note that the input expression could be quite complex involving many func= tions, such as trigonametric, logarithms and other functions. However, the = exponent itself (2 in the above example) is always going to be an integer. > > Thanks Say, Sqrt[x^2 + 1] + Sin[x^4*Tan[x^8]]] is your expression, then you could try In[36]:= Max[Cases[Log[Sqrt[x^2 + 1] + Sin[x^4*Tan[x^8]]], (x_)^(a_Integer) :> a, Infinity]] Out[36]= 8 or In[37]:= Max[(Exponent[#1, x] & ) /@ Cases[Log[Sqrt[x^2 + 1] + Sin[x^4*Tan [x^8]]], x^_Integer, Infinity]] Out[37]= 8 You can take an idea of how the above one liners work if you decompose the codes. You also the built in functions TreeForm and FullForm to this end Dimitris