I need the second derivative of f(x)= (x+1)/ sqrt[(x^2) +1]

I got f'(x)= (1-x) / [(x^2) +1]^(3/2)

Solution for f''(x)=[(2x^2) - 3x -1] / [(x^2) +1]^(5/2)

I tried the Quotient Rule but I do not get the solution...

Can someone explain how to get to the solution?