y = (1+x²)/(1-x)y' = [2x(1-x) + (1+x²)]/(1-x)²y'= (1+2x-x²)/(1-x)²dy = [(1+2x-x²)/(1-x)²]dx
y = (1+x^2)/(1-x) y' = [2x(1-x) + (1+x^2)]/(1-x)^2 = (1+2x-x^2)/(1-x)^2dy = (1+2x-x^2)dx/(1-x)^2
