For the first question, I get x=1, -1 for critical points. The interval of increase is -1<x<1. The local extrema are (-1,-1/2) and (1,1/2)

The H.A is y=0 and the curve crosses it at (0,0)? I could be wrong, here's the question differentiated-f'(x)=1-x^2/(1-x^2)^2

For the second one, I get the slope to equal 1/-5 and y intercept to be -14/5?