Use the quotient rule to find f'(x) from f(x).
f(x) = g(x)/h(x)
f(x) = 4/(x^2+1) Hence g(x) = 4 and h(x) = (x^2+1)
Then f'(x) =
g'(x)h(x)-g(x)'h(x)
-----------------
h(x)^2
So f'(x) =
(0)(x^2+1)-(4)(2x)
-------------------
(x^2+1)^2
Hence =
-8x
-----------
(x^2+1)^2
Now do the same for f '' (x).
Albert Einstein?


