Question

derivative and simplifying problem :(

Answer 1

\[\frac{ x }{ \sqrt{x^2+1} }\]

Answer 2

\[\frac{ \sqrt{x^2+1}-\frac{ 1 }{ 2 }(x^2+1)^{-1/2}(2x) }{( \sqrt{x^2+1)^2} }\]

Answer 3

forgot an x i think

Answer 4

ya

Answer 5

rest is fine

Answer 6

how does wolfram get this

Answer 7

http://www.wolframalpha.com/input/?i=derivative+%28x%29%2Fsqrt%28x%5E2%2B1%29