Re: simplifying rational expressions

*To*: mathgroup at smc.vnet.net*Subject*: [mg61111] Re: simplifying rational expressions*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Tue, 11 Oct 2005 03:20:04 -0400 (EDT)*Organization*: The Open University, Milton Keynes, UK*References*: <did2q0$qde$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

krily wrote: > If someone could be so kind as to show me how to simplify the following: > > [(t^4-1)(t^2-9)(t-9)^2]/[(t^4-81)(t^2+1)(t+1)^2] > First, use the correct syntax to group expressions: right and left parentheses rather than right and left squared brackets. In[1]:= expr = ((t^4 - 1)*(t^2 - 9)*(t - 9)^2)/((t^4 - 81)*(t^2 + 1)*(t + 1)^2) Out[1]= ((-9 + t)^2*(-9 + t^2)*(-1 + t^4))/((1 + t)^2*(1 + t^2)*(-81 + t^4)) Then, *Cancel* could be a good start to simplify rational expression In[2]:= Cancel[expr] Out[2]= ((-9 + t)^2*(-1 + t))/((1 + t)*(9 + t^2)) Hope this helps, /J.M.