# Revision history [back]

### Sage for (very) undergrad students

Hi all

Today I had hard time with Sage because

sage: f(x)=1/(1-x**2)
sage: g(x)=f.integrate(x)
sage: g(0.5)
0.549306144334055 - 1.57079632679490*I
sage: g
x |--> -1/2*log(x - 1) + 1/2*log(x + 1)


This is not the primitive my students are expecting : they expect 1-x on the denominator. In particular they are not expecting :

sage: ln(-1)
I*pi


I had other some small problems like that with Sage like the difference between +Inf,-Inf and Inf when computing a limit (in the latter case my students are expecting "does not exist").

So my question is : is there a way to ask Sage to behave like a very undergrad student is expected to behave ? (ex : ln(-1) does not exist) Is there a way to say «I'm an undergrad student and I want Sage to solve my homework of basics calculus» ?

Do you have experience/habits to prevent Sage to mislead students by its unexpected answers (however mathematically correct) ?