f(x)= x over root x^2+1 (all of its in a root)

I can get this far (x^2+1)^1/2(1) - (x)(1/2)(x^2+1)^-1/2(2x) all over (x+1)^1/4

this breaks down to (now i'm not sure if this is right) (x^2+1)^1/2-x^2 over (x+1)^1/4(x^2+1)^1/2

am i even on the right track?