I have calculated the inequality (1-x^2)/(x^2-3x+2)>0 and the result was -1<x<2 But if x is 1 then the denominator and the numerator are both zero. X=1 does not satisfy the equation however it is in the solution set. Should I get another calculator because this is a pretty easy operation to do for TI 89 and it should not fail in my opinion. Can someone inform me about this topic and I also want to know if anyone has experienced similar problems with a calculator from TI. I have also included screen captures.

Thanks in advance for help.