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Trouble with rules

Posted 9 years ago
2 Replies
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Hi all,

I am new to mathematica and am trying to get a hang of rules. Here is what I am trying to do.

I wanted to show in Mathematica that the Limit of $$ \begin{align*} \lim_{R \to \infty } \frac{e^{a R}}{e^R} = 0 & & | a | < 1 \end{align*} $$

So what I tried in Mathematica is Limit[ Exp[a*R] / Exp[R], R -> [Infinity]]. But I don't know how to force it use a rule like this: Abs[a]<1

Anyone know what would be the proper syntax in Mathematica to do the above?

Thanks in advance.

POSTED BY: larry davis
2 Replies

One thing to be aware of is that in Mathematica, when one mentions "rules" one is typically referring to things with head Rule or a List thereof. What you are dealing with in this case is assumptions.

I realize this is just nomenclature and not in general a big deal. But it is helpful to have the right terminology in the subject header since, for many people, that can determine what gets read.

POSTED BY: Daniel Lichtblau
In[2]:= Limit[Exp[a*r]/Exp[r], r -> \[Infinity], 
 Assumptions -> {Abs[a] < 1}]

Out[2]= 0
POSTED BY: Frank Kampas
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