finding Df and variation and calculing limite but ...

[wassims]

helllo
i find a program in hp website
it find the domain of definition and tracing (graph) the table of variation and calculating the limites (lim x-->) but it does some error
lik this
try to enter this function
(2x^2+4x+1)/(x^2+2x)
he give the Df like this
]-infinity.0[U]0.+infinity[
and iths inccorect the correct DF is
]-infinity.-2[U]-2.0[U]0.+infinity[
and some times he can't find the Df if the function is large or contenaing EXPONENTIAL OR LOGHARIME
and now if there's any one can devellope this programe o give me another do all this funtions(limite.variation table.derivative.DF) .
tnx for all
and sorry for my english becaus ispeak just french or arabic
and this is the link for the prgrame
DOWNLOADhttp://www.hpcalc.org/hp48/programming/hacker/etude.zip
http://www.hpcalc.org/hp48/programming/hacker/etude.zip