Hi I'm studying for an upcoming exam and I have to find the Maclaurin series for f(x)= ((1-x^2)/(1+x^2)) And I gotta admit i feel stuck. I know i need to find the terms f(0) +f'(0) +f''(0)/2 etc. Frist of all I can't find the first derivative f´(x) because my TI89 calculater comes up with a Dimension error. Sexond: As an alternative I really can't see which other known function/series i could use to substitute the function into. Please help me out - I'd appreciate it a lot!