Re: Output display of exponential function in Mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg62710] Re: Output display of exponential function in Mathematica*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Fri, 2 Dec 2005 05:53:08 -0500 (EST)*Organization*: The Open University, Milton Keynes, UK*References*: <dmbqgl$q9h$1@smc.vnet.net> <dmlvu8$mbp$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

New Guy wrote: > I'm trying to just check and see if I got a whole bunch of > even-numbered study exercises right on exponents and natural logs. > The answers to the odds are in the book. > > As an example, LN(1/e^2) equals what? > > My answer is -1/2. > > In mathematica, I tried Simplify[LN(1/e^2)] and it just spit the same > thing out as the output. I also tried a couple of variations of > Solve[LN[1/e^2] = X] with essentially the same result > > How would you get Mathematica to verify that the answer is -1/2. Use the correct syntax :-) The natural logarithm of the number a, say, is written Log[a]. Check http://documents.wolfram.com/mathematica/functions/Log Now, the base of the natural logarithm is written E (capital e). Therefore, you can check your answer with In[1]:= Log[1/E^2] Out[1]= -2 (Hint: Log[1/E^2] <==> Log[1] - Log[E^2]...) Hope this helps, /J.M.